This thesis mainly deals with some biochemical aspects regarding the efficacy of novel platinum anticancer compounds alone and in combination with mangiferin, as part of a broader study in which both chemistry and biochemistry are involved. Various novel diamine and N-S donor chelate compounds of platinum II and IV have been developed in which factors such as stereochemistry, ligand exchange rate and biocompatibility were considered as additional parameters. In the first order testing, each of these compounds was tested with reference to their “killing” potential by comparing their rate of killing, over a period of 48 hours with those of cisplatin and oxaliplatin. Numerous novel compounds were tested in this way, using the MTT cell viability assay and the three cancer cell lines MCF7, HT29 and HeLa. Although only a few could be regarded as equal to or even better than cisplatin, CPA7 and oxaliplatin, the testing of these compounds on cancer cells provided useful knowledge for the further development of novel compounds. Three of the better compounds, namely Yol 25, Yol 29.1 and Mar 4.1.4 were selected for further studies, together with oxaliplatin and CPA7 as positive controls, to obtain more detailed knowledge of their anticancer action, both alone and when applied in combination with mangiferin. In addition to the above, resistant cells were produced for each of the three different cell lines tested and all the selected compounds, both in the presence and absence of mangiferin. The effects of these treatments on the activation of NFĸB when applied to normal and resistant cell lines were also investigated. All the compounds induced apoptosis in the cell lines tested as well as alter the DNA cycle at one or more phase. Additionally, combination of these compounds with mangiferin enhanced the above-mentioned effects. Mangiferin decreases the IC50 values of the platinum drugs by up to 3.4 times and, although mangiferin alone did not induce cell cycle arrest, the presence of mangiferin in combination with oxaliplatin and Yol 25 shows an earlier and greatly enhanced delay in the S-phase, while cells treated with CPA7, Yol 29.1 and Mar 4.1.4 in combination with mangiferin showed a later, but greatly enhanced delay in the S-phase. It was also found that mangiferin acts as an NFĸB inhibitor when applied in combination with these drugs, which, in turn, reduces the occurrence of resistance in the cell lines. Resistance to oxaliplatin was counteracted by the combination with mangiferin in HeLa and HT29, but not in MCF7 cells, while resistance to CPA7 was only counteracted in the MCF7 cell line. Yol 25 and Mar 4.1.4 did not seem to induce resistance in HeLa and MCF7 cells, but did in HT29 cells, whereas Yol 29.1 caused resistance in HeLa and HT29 cells, but not in MCF7 cells. Finally, an effort was made to evaluate the different compounds by comparing them with respect to their properties relating to anticancer action with and without the addition of mangiferin.

This dissertation mainly deals with some biochemical aspects regarding the efficacy of novel platinum anticancer compounds, as part of a broader study in which both chemistry and biochemistry are involved. Various novel diamine and N-S donor chelate compounds of platinum II and IV have been developed in which factors such as stereochemistry, ligand exchange rate and biocompatibility were considered as additional parameters. In the first order testing, each of these compounds was tested with reference to their “killing” potential by comparing their rate of killing, over a period of 48 hours with those of cisplatin and oxaliplatin. Some 80 compounds were tested in this way. Although only a few could be regarded as equal to or even better than cisplatin and oxaliplatin, the testing of these compounds on cancer cells provided useful knowledge for the further development of novel compounds. Four of the better compounds, namely Y9, Y14, Y16 and Lt16.2 were selected for further studies to obtain more detailed knowledge of their anticancer action, including some flow cytometric studies. In addition to the above, cisplatin resistant cells were produced for each of the three different cell lines tested, namely, HeLa, HT29 and MCF7 cancer cell lines, by intermittent and incremental exposure to cisplatin (all the cell lines tested became resistant to cisplatin). Each of the selected compounds were exposed to the cells in the same manner, in order to attempt the induction of resistance against these compounds in the three cell lines tested (i.e. whether these cells will become resistant to the various compounds). Each of these selected platinum containing compounds were subsequently tested against the “cisplatin resistant” cell lines in order to determine their efficacy against such cells. One such compound could be singled out, since cervical cancer cells (HeLa cells) do not become resistant to it. This behaviour is similar to that of oxaliplatin against cervical cancer and colon cancer (HT29) cells (oxaliplatin is the number one treatment for colon cancer at present). This compound also proved to be more active against cisplatin resistant cell lines. It was found that all the compounds induced apoptosis in the cell lines tested as well as inhibit the DNA cycle at one or more phase. Finally, an effort was made to evaluate the different compounds by comparing them with respect to their properties relating to anticancer action.

The drug development process, especially for anti-cancer therapies, continues to be highly inefficient. The current preclinical drug evaluation paradigm of human monolayer in vitro culture followed by small animal in vivo models results in a roughly 90% failure rate in clinical trials involving actual cancer patients. Our hypothesis then, is that there is a clear need for engineered, 3D, healthy and tumor tissue models capable of recapitulating patient physiology and disease, allowing for more accurate preclinical evaluation of anti-cancer drugs. Our hope, is that tissue engineering can provide us with valuable new insights into drug responses, over what we can currently achieve with existing models. Here, we present a new multi-tissue organs-on-a-chip microfluidic platform, Inter-Organ, designed to allow more comprehensive recapitulation of the disease seen in patients. We developed bioengineered tissues of primary and metastatic tumors across three cancer types, and integrated them into the Inter-Organ platform alongside healthy tissues like cardiac muscle known to cause failures in clinical trials for off-target drug toxicities. Overall, the development of these new cancer models and their culture in the Inter-Organ platform allowed us to more accurately predict the success of various drugs in clinical trials than existing models could. Finally, this tissue engineering approach allowed us to explore the relationships between specific constituents of the tumor microenvironment, recapitulate complex cancer processes like metastasis previously only done in small animal models, and identify new potential diagnostic and therapeutic targets.

Breast cancer is the most common cancer in women, accounting for almost one-thirdof new cancer diagnoses in the United States. The mortality rate has decreased by 42% since 1989 due to early diagnosis, improvements in imaging techniques and treatment regimens. Despite all the advances in imaging modalities, there is still a need for a non-invasive, nonionizing, and low-cost diagnosis technique with high sensitivity and specificity to reduce the rate of invasive biopsies. For individuals diagnosed with locally advanced breast cancer and early-stage breast cancer, neoadjuvant chemotherapy (NACT) has become the standard of care. Pathologic complete response (pCR) is the ideal outcome of NACT, which is correlated with the prognosis and overall survival of the patients. The pCR is achieved in only about 15-20% of patients determined at the time of surgery; therefore, most patients receive a treatment that is not beneficial for them and has considerable side effects. Thus, early detection and monitoring of breast tumor response to NACT is critical for treatment planning and improving overall survival. Ultrasound-based elasticity imaging techniques have gained interest in the clinic due to their potential to provide qualitative and/or quantitative information about tissue stiffness, which is presently not unachievable with standard ultrasonography. These techniques rely on the fact that a breast tumor’s stiffness or Young’s modulus is higher than that of the surrounding normal tissues. In this dissertation, the clinical feasibility of a technique called harmonic motion imaging (HMI) for breast tumor classification, as well as for NACT response prediction and monitoring of solid tumors is investigated. HMI is an ultrasound-based elasticity imaging technique that evaluates the mechanical properties of the underlying tissues by inducing amplitude modulated (AM) displacements at a specific frequency. First, we investigated whether HMI can characterize and differentiate human breast tumors based on their relative stiffness. We enrolled female patients with benign and malignant tumors and imaged them with a clinical HMI system. The malignant tumors were found to be associated with lower HMI displacements or higher stiffness than the benign tumors. Then, in order to verify our clinical findings, we estimated HMI displacements in the postsurgical breast specimens from the same subjects and compared them against the in-vivo estimations. Our findings indicated that HMI successfully differentiated tumors from the surrounding tissue in both ex-vivo and in-vivo conditions, with an excellent correlation between the results in the two different settings. Second, we introduced and characterized a new HMI setup consisted of a multi-element focused ultrasound transducer (FUS) with electronic beam steering capability. Therefore, instead of mechanical translation of the HMI setup, the acoustic force could be electronically steered in the volumetric space to accelerate the data acquisition. A pulse sequence was developed to drive the HMI transducers assembly, the FUS and imaging transducer, using a single ultrasound data acquisition system to have a compact setup that is more applicable for clinical settings. The data acquisition was further improved by investigating the effect of AM frequencies on the quality of the HMI images and tumor detection. We found that higher AM frequencies are needed in order to improve the detection and characterization of small and stiff inclusions. On the contrary, soft and large inclusions are better resolved at lower AM frequencies. Lastly, we investigated the feasibility of using HMI for early prediction of response to neoadjuvant chemotherapy in cancer mouse models and breast cancer patients. We acquired longitudinal HMI images from pancreatic and breast cancer murine tumors during treatment with chemotherapeutic drugs and monitored the changes in the mechanical properties of the tumors. The tumors were found to soften when responsive to treatment, followed by the stiffness increase in the case of drug resistance. However, the untreated mice underwent steady stiffening of the tumors. Next, we imaged breast cancer patients at different timepoints during their chemotherapy treatment. We found that tumors in the patients who achieved pCR had higher pre-treatment stiffness and higher softening from pre-treatment to a short-interval follow-up on treatment compared to the ones in patients with residual cancer cells at the completion of treatment. These findings indicate the promising potential of HMI in the early prediction of solid tumor response to chemotherapy interventions.

Lectins (hemagglutinins) are a type of proteins that could recognize different sugar structures and specifically initiate reversible binding with them. Though they have been universally found in a variety of organisms, they are exceptionally abundant in legumes. From the initial finding of agglutinating red blood cells to the discovery of recognizing carbohydrates on cell membranes, multiple functions of lectins have been gradually unveiled by numerous researchers across a century. Based on its carbohydrate-binding property, lectins have found great value in the study of glycomics. Many lectin-based biological tools, like lectin affinity chromatography, lectin blotting, lectin histochemistry, lectin microarray and lectin-based biosensor have been developed and applied to the study of glycoproteins. Besides, lectins are also reported to be potential agents for anti-insect, anti-fungi, anti-HIV, anti-bacterial and anti-tumor applications. / The present study focuses on the isolation of a new hemagglutinin from an edible legume, exploration of its anti-colorectal cancer effect and mechanisms, its cytokine inducing function and anti-HIV activities. The protein was purified by liquid chromatography techniques which entailed affinity chromatography on Affi-Gel Blue Gel, ion exchange chromatography on Mono Q and gel filtration on Superdex 75 with an FPLC system. The hemagglutinating activity of this hemagglutinin was demonstrated to be ion-dependent and stable over a wide range of temperatures (20-60℃) and pH (2-11) values. Like most of the lectins or hemagglutinins, this novel hemagglutinin could also attenuate the activity of HIV-1 reverse transcriptase. / This hemagglutinin could potently suppress the proliferation of colorectal carcinoma HCT116 cells and colorectal adenocarcinoma HT29 cells. It induced cell cycle arrest in G0/G1 phase, downregulated the expression of Cyclin D1 and upregulated P21expression. The protein initially bound on the cell membranes most probably through glycoproteins and subsequently entered the cytoplasm, which was achieved as early as 3h post treatment. The hemagglutinin was found to be preferentially localized in Golgi apparatus and initiated aggregation of the Golgi apparatus, which may possibly attenuate its protein processing capacity by reducing total superficial area or even partially blocking the transportation of proteins from the endoplasmic reticulum (ER). The impaired protein reception ability of Golgi apparatus may lead to the protein accumulation in the ER and induce cell apoptosis. Accordingly, two ER stress sensors (IRE1α and ATF6) and one late product of ER stress (CHOP) were found to up-regulated. Apoptosis-inducing effect of this hemagglutinin on HT29 and HCT116 cells were further confirmed using methods based on different principles. Cells treated with the hemagglutinin were observed to undergo obvious chromatin condensation, mitochondrial membrane depolarization and phosphatidylserine exposure. An apoptosis initiator (Apaf-1) and one important indicator (cleaved PARP) of cell apoptosis were accordingly detected. Besides, intraperitoneal administration of this hemagglutinin to colorectal tumor bearing nude mice could slow down the growth of tumors. / At last, this hemagglutinin exerted an immunomodulatory function on splenocytes by stimulating the mRNA expression level of interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-1 beta (IL-1β), interferon- gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α). Secretion of IL-1β and IL-2 from splenocytes also increased with the concentration of this hemagglutinin. / In a short conclusion, we have isolated a new hemagglutinin with anti-HIV RT, anti-colorectal cancer and immunomodulatory activities. / 凝集素（血凝素）是一类能够识别不同糖结构并能和它们发生可逆性结合的蛋白。虽然他们在许多生物体内均有发现，但这类蛋白在豆科植物中的含量尤其丰富。经过一个多世纪来众多研究者的努力，从最初认识到其具有红血细胞凝集功能到糖类识别作用，凝集素的诸多功能已被逐步挖掘。基于其独特的糖结构识别特性，凝集素在糖组学的研究中具有重大意义。许多基于凝集素的生物方法，如凝集素亲和层析法，凝集素印迹法，凝集素组织化学，凝集素生物芯片以及基于凝集素的生物传感器已被研究出来, 并用于研究糖蛋白。除此之外，研究表明，凝集素还具有抗虫，抗真菌，抗HIV，抗细菌和抗癌等活性。 / 该凝集素可以极大抑制结肠直肠癌HCT116细胞和结直肠腺癌HT29细胞增殖，引发细胞周期停滞，分别下调和上调Cyclin D1和P21的表达。该蛋白极有可能首先通过和细胞表面的糖蛋白结合而附在细胞膜上，然后进入细胞内。该过程可在往细胞培养液内加入该蛋白后的3小时内完成。该凝集素优先与细胞内的高尔基体结合，随后引发高尔基体聚集。该聚集作用可能会通过减少高尔基体总表面积甚至阻塞内质网和高尔基体间的蛋白运输，进而减弱高尔基体处理蛋白质的能力。当高尔基体接受蛋白的能力降低时，蛋白可能会堆积在内质网上并进一步引发细胞程序性死亡。相应地，两个内质网应激感受蛋白IRE1α和 ATF6以及内质网应激后期产物CHOP均被发现上调。该凝集素对HT29细胞和HCT116细胞的凋亡诱导作用采用不同的方法进行了进一步的确认，这些方法都是基于不同检测原理进行的。结果表明，该凝集素可导致细胞产生明显的染色质凝缩，线粒体膜电位去极化和磷脂酰丝氨酸外翻。与此相应地，凋亡启动蛋白Apaf-1和凋亡后期蛋白(被剪切的PARP)可在处理后的细胞中检测到。通过腹腔注射的方法给接种大肠癌细胞的裸鼠给药可降低肿瘤的生长速度。 / 本研究的工作包括：从一种可食用豆类中提取一种新的凝集素；检测其抗大肠癌的作用和机制；研究其细胞素诱导作用以及抗HIV活性。该蛋白采用液相色谱法分离提纯，其中包括亲和层析柱Affi-Gel Blue Gel, 离子交换层析柱Mono Q 和凝胶层析柱Superdex 75，后两种层析法在FPLC系统上操作。该蛋白的红血细胞凝集作用具有金属阳离子依赖性，并在20-60℃和pH2-11范围内保持活性稳定。像许多其它的凝集素一样，该蛋白也可以削弱HIV逆转录酶活性。 / 最后，该蛋白还具有免疫调节作用，它可促进白细胞介素-2，白细胞介素-6，白细胞介素-1β，干扰素-γ和肿瘤坏死因数-α在mRNA水平上的表达并刺激白细胞介素-2和细胞介素-1β的分泌。 / 综上所诉，本研究分离提纯了一种新凝集素，它具有抗HIV，抗大肠癌和免疫调节作用。 / Dan, Xiuli. / Thesis Ph.D. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 153-170). / Abstracts also in Chinese. / Title from PDF title page (viewed on 05, October, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

Chemotherapy in childhood cancer patients is associated with reduced bone density that can result in osteoporotic fracture in survivors. A significant proportion of paediatric patients experience a reduction in plasma 25 - hydroxyvitamin D3 [ 25 ( OH ) D3 ] and 1,25 - dihydroxyvitamin D3 [ 1,25 ( OH ) 2D3 ] levels during treatment, the basis of which is unknown. A balance between the bioactivation and degradation of 1,25 ( OH ) 2D3 is responsible for maintaining homoeostatic levels of 1,25 ( OH ) 2D3 at the correct set - point. Whereas the cytochrome P450 enzyme, CYP27B1 ( 25 - hydroxyvitamin D3 1 α - hydroxylase ), catalyses the hydroxylation of the precursor 25 ( OH ) D3 to generate 1,25 ( OH ) 2D3, catabolic inactivation and cleavage of 1,25 ( OH ) 2D3 is achieved by the mitochondrial cytochrome P450 enzyme, 25 - hydroxyvitamin D3 24 - hydroxylase ( CYP24 ), which is highly expressed in bone and kidney cells. Since many of the signalling pathways which regulate the expression of CYP24 are also activated by chemotherapeutic drugs, we hypothesised that the drugs could cause the degradation of plasma 25 ( OH ) D3 and 1,25 ( OH ) 2D3 by increasing CYP24 expression, the principal means of facilitating the bio - inactivation and degradation of plasma 25 ( OH ) D3 and 1,25 ( OH ) 2D3. Using the kidney cell - lines, COS - 1 and HEK293T cells, we now report that chemotherapeutic drugs, represented by daunorubicin hydrochloride ( an anthracycline antibiotics ), etoposide and vincristine sulphate ( vinca alkaloids and related compounds ) and cisplatin ( an alkylating agent ), were able to enhance CYP24 promoter activity in kidney cell lines transfected with a CYP24 promoter - luciferase construct, either by themselves or in the presencedaunorubicin hydrochloride and etoposide, two of the strongest inducers of CYP24 promoter activation under our experimental conditions, demonstrate that these drugs acted in a concentration - dependent manner. In addition to stimulating promoter activity on their own, the drugs also amplified the induction of the CYP24 promoter by 1,25 ( OH ) 2D3. Synergistic increases were generally observed when the cells were treated simultaneously with 1,25 ( OH ) 2D3 and a drug. The two kidney cell lines generally responded in a similar manner when challenged with the drugs, either in the presence or absence of 1,25 ( OH ) 2D3. Interestingly, the hydroxylated derivative of daunorubicin hydrochloride, doxorubicin hydrochloride which is also a commonly used chemotherapeutic drug, had no effect of promoter activity. Further studies with daunorubicin hydrochloride demonstrated that the effects of the drug per se were not mediated by oxidative stress and the vitamin D receptor was not required for daunorubicin hydrochloride per se to stimulate CYP24 promoter activity. However, daunorubicin hydrochloride caused a modest increase in the expression of the vitamin D receptor and this could contribute to its synergistic activity with 1,25 ( OH ) 2D3. In the presence of etoposide, there was also a tendency for the kidney cells to express higher levels of the vitamin D receptor. A key role for the extracellular signal - regulated protein kinase ( ERK ) 1, ERK2 and ERK5 mitogen - activated protein ( MAP ) kinases was demonstrated for the inductive action of daunorubicin hydrochloride and etoposide, with CYP24 promoter - specific transcription factors located in the first - 298bp being likely targets of the ERK activity. Studies with a dominant negative mutant of MKK4, one of the two immediate upstream activators of the c - jun N - terminal kinase isoforms, demonstrated that this MAP kinase also played a crucial role in inductive actions of the of 1,25 ( OH ) 2D3. Dose - response studies with drugs. Consistent with their use in anti - cancer therapy, all of the above drugs killed the human promyelocytic HL60 leukaemic cells at very low concentrations but had no effect on the viability of kidney or liver cells, either at concentrations used in our experiments or at higher levels. Our data provide novel biochemical evidence that some of the commonly used chemotherapeutic drugs could cause an increase in the transcriptional activation of the promoter, most likely via the MAP kinases activating the transcription factors which bind to the CYP24 promoter. Such an effect could contribute to the reduction in plasma 25 ( OH ) D3 and 1,25 ( OH ) 2D3 in some of the patients undergoing chemotherapy. / Thesis (Ph.D.)--School of Paediatrics and Reproductive Health, 2005.

TCP-1是一种新型的定向于肿瘤血管的多肽，通过小鼠体内的噬菌体展示技术筛选得到。在之前的研究中，我们已证明TCP-1具有定向于肿瘤血管并有效靶向运输抗肿瘤药物和显像剂的特性。本研究的目的是进一步研究在原位结肠癌模型中定向运输抗肿瘤药物肿瘤坏死因子(TNFα)，以及在结肠癌临床样本中运输显像剂异硫氰酸荧光素(FITC)的能力。并对TCP-1与肿瘤坏死因子的融合蛋白TCP-1/TNFα的抗肿瘤机制进行阐述。 / 本研究中，我们首先尝试用TCP-1作为载体，将增强绿色荧光蛋白靶向运输至肿瘤血管。结果证明TCP-1可以成功将蛋白运输到在肿瘤血管而非其它正常的组织器官上。TCP-1还可以靶向运输肿瘤坏死因子并增强其抗肿瘤作用。和肿瘤坏死因子比较，融合蛋白TCP-1/TNFα处理组的凋亡细胞数量增多，肿瘤微血管数目减少，并且无明显毒副作用。与结肠癌的一线化疗药物5-氟尿嘧啶(5-FU)联合给药后，与TNFα与5-FU联合给药相比较，融合蛋白TCP-1/TNFα联合5-FU在以下方面具有更明显的作用：抑制肿瘤生长，增加肿瘤细胞凋亡和抑制肿瘤细胞增殖，促进肿瘤血管正常化，升高瘤内免疫细胞以及减轻骨髓和脾内的免疫抑制反应。经检测TCP-1的靶向运输增加了瘤内的TNFα以及5-FU的浓度。这些都表明TCP-1不但可以靶向运输TCP-1/TNFα至肿瘤血管，还可以增加CD8+细胞的浸润增加瘤内免疫反应以及增加血管对抗肿瘤药物的通透性。以上都对抗肿瘤起到重要作用。 / 在临床的结肠癌样本中，TCP-1对肿瘤血管的结合能力也得到了证实。48.98%的结肠癌样本对TCP-1的结合为阳性。统计学分析显示TCP-1的结合与结肠癌的分期和肿瘤位置有关，对于N2期，位于乙状结肠的肿瘤的结合尤为明显。本研究的主要目的是将分离鉴定出的TCP-1发展成为结肠癌的生物标记，并且作为运输抗肿瘤药物和显像剂的载体应用于结肠癌的诊断和治疗中。鉴于TCP-1的靶向运输特点，将会有机会研发更多的抗肿瘤药物，同时增强传统化疗药的抗肿瘤作用。这些都可以优化肿瘤治疗的方案。综上所述，TCP-1是一种在结肠癌治疗诊断中具有广阔前景的多肽。 / TCP-1 is a novel vasculature-targeting peptide. It was discovered through the in vivo phage library selection in mice. It was demonstrated that TCP-1 peptide exhibited a homing ability to the neovasculature of colon tumors and was capable of efficiently delivering imaging agents and chemotherapeutic drugs to this target site. The current study is to further investigate the targeting ability of TCP-1 to deliver a known immunomodulator, tumor necrosis factor α (TNFα) as an example of anti-cancer drug in an orthotopic colorectal cancer (CRC) model and fluorescein isothiocyanate (FITC) as imaging agent for testing the binding capacity for tumors in colorectal cancer patients. The mechanisms for the action of this novel biologic TCP-1/TNFα in the treatment of colon cancer in mice were also defined. / In this study, we observed that TCP-1 peptide delivered enhanced green fluorescent protein (EGFP) only to tumor blood vessel other than normal organs after TCP- 1/EGFP injection. This was not observed after EGFP injection. This finding showed that TCP-1 can deliver biologic protein to the tumor blood vessels. Furthermore, results from TNFα or TCP-1/TNFα targeted delivery experiments showed that TCP- 1/TNFα displayed stronger anti-cancer effects than TNFα alone on the induction of apoptosis and reduction in number of microvessels in the tumors, without significant effect in systemic toxicity. In the combined therapy with 5-fluorouracil (5-FU), a standard drug for colon cancer treatment, pretreatment with low dose (1 ng TNFα /mouse) of TNFα or TCP-1/TNFα potentiated the anti-cancer action of 5-FU. In this regard, TCP-1/TNFα could significantly reduce tumor size and weight, increase number of apoptotic cells, inhibit tumor cell proliferation, normalize tumor blood vessels, facilitate infiltration of immune cells to tumor mass and attenuate immunosuppression in bone marrow and spleen. Moreover, TCP-1 could significantly increase intratumoral levels of TNFα and 5-FU. It was also suggested that TCP-1 could selectively deliver TNFα to the tumor blood vessels and modulate the immune response by increasing CD8+ cells infiltration to tumors and increase vascular permeability to 5-FU. These observations may be the key actions to reduce tumor growth. / The binding ability of TCP-1 was also detected in clinical samples from colorectal cancer patients in which 24/49 (48.98%) tumor tissues were positive with TCP-1 binding signal. Statistical analysis showed that TCP-1 had a strong and significant binding with colorectal cancer at the N2 stage among the different colorectal cancer stages (P=0.028) and location in the colon at the sigmoid (P<0.001). / Our study also focused on the isolation and identification of the binding molecule of TCP-1 in order to develop it into a biomarker for CRC and using TCP-1 as a carrier in delivering anti-cancer drugs and imaging agents to colon tumors for cancer therapy and diagnosis. With the homing property of TCP-1 on colon tumor blood vessels, new types of anti-cancer drugs will be developed and their combinations with conventional chemotherapy drugs will optimize the therapeutic outcome and improve regimen of treatment for CRC. Taken together, TCP-1 peptide appears to be a promising agent in molecular imaging and drug delivery for CRC diagnosis and therapy. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Lu, Lan. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 157-177). / Abstracts also in Chinese. / Lu, Lan.

Colorectal cancer (CRC) is one of the most common malignancies worldwide. However, adjuvant chemotherapeutic agents exhibit poor accumulation in the tumor mass and frequently result in serious side effects due to nonspecific damage to normal organs. Therefore, the development of more selective anticancer drugs with targeted delivery to tumor sites is the current trend in cancer therapies. Among these sites, tumor neovasculature is an attractive target for anticancer agents. It is because tumor growth is largely limited by blood supply which is dependent on the extent of angiogenesis in the tumor. / Experimental analysis suggested that TCP-1 phage and synthetic TCP-1 peptide specifically homed to colorectal cancer tissues and co-localized with the tumor vasculature. Moreover, TCP-1 peptide also recognized the vasculature of human colorectal cancer specimens. Subsequently, the homing abilities of TCP-1 phage were extensively tested in other cancer models. Results showed that TCP-1 peptide could also target the vasculature of orthotopic gastric cancer induced by human colon cancer cell line (MKN45) in BALB/c nude mice. Meanwhile, TCP-1 phage exhibited binding activity to colorectal cancer cells such as colon 26 and SW1116. TCP-1 peptide could carry a pro-apoptotic peptide into these cells and markedly enhanced its pro-apoptotic action. / In summary, we have used the phage display technology to isolate two unique peptides TCP-1 and TCP-2, which targeted the vasculature of orthotopic colorectal cancer and also recognized the vasculature of human colorectal cancer. Moreover, they could deliver fluorescein or pro-apoptotic peptide only to the tumor vasculature but not to other normal tissues, for imaging detection and targeted therapy. In conclusion, both TCP-1 and TCP-2 may have significant clinical applications as carriers in diagnostic imaging and ligand-mediated targeted therapy for human colorectal cancer. / Similarly, TCP-2 phage or its peptide also targeted specifically the orthotopic colorectal cancer, and co-localized with the tumor vasculature in mice. Meanwhile, TCP-2 peptide recognized the vasculature of human colorectal cancer specimens. FITC-labeled TCP-2 peptide could also be used to detect cancer tissues in tumor-bearing mice. / To identify specific ligands targeting the tumor neovasculature, in vivo phage display technology has been extensively used. Several dozens of peptides homing to normal or diseased vasculature have been identified through this technology. However, these peptides target mainly the tumors growing at distant sites but not at the primary organ, thus limiting their clinical application. To obtain specific peptides targeting the neovasculature of colorectal cancer growing in situ, we established an orthotopic colorectal cancer model in normal BALB/c mice by using syngeneic colon cancer cells (colon 26). Subsequently, in vivo phage display technology was utilized to isolate peptides which specifically recognized the vasculature of the cancer. Four peptides (termed TCP-1, 2, 3, 4) were enriched more than once after four-round selections. Further investigation disclosed that TCP-1 and TCP-2 phages had relatively stronger binding abilities to cancer tissues among the four phage clones. They were chosen for further study. / We further demonstrated that TCP-1 could serve as a carrier for image detection and drug delivery. FITC-labeled TCP-1 could specifically produce a strong fluorescence signal in the tumors after intravenous injection into the orthotopic tumor-bearing mice. Moreover TCP-1, when conjugated with a pro-apoptotic peptide, could also specifically induce apoptosis of tumor vasculature in vivo. / Li, Zhijie. / Adviser: Cho Chiltin. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 194-221). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Chemotherapy persists as one of the mainstays of breast cancer treatment, particularly for triple-negative breast cancer which currently has no targeted treatment methods. While chemotherapy is beneficial for killing the malignant tumor cells, it leads to the release of damage-associated molecular patterns into the tumor microenvironment. Damage-associated molecular patterns are a contributing factor to cancer-related inflammation which can potentiate metastatic spread through several mechanisms such as the development of tumor microenvironments at metastastic sites. These damage-associated molecular patterns include nucleic acids, nucleic acid-associated lipids and vesicles, cytokines, and proteins such as high mobility group protein B1. Polyamidoamine (PAMAM) is a biodegradable, water-soluble dendrimer polymer with the ability to possess different charges and sizes depending on its terminal branches and degree of branching (i.e. generation number), respectively. Amine-terminated PAMAM-NH2 is positively charged and can bind to circulating DNA and RNA. Since most DAMP molecules are negatively charged, I hypothesized that a polycation such as PAMAM-NH2 would be an efficient nanomaterial to remove pathogenic NA DAMPs generated by chemotherapy. Building on this dendrimer, we synthesized modified cationic PAMAM-generation 3 derivatives with an aim to balance toxicity with NA-binding affinity and capacity to encapsulate chemodrugs. Our results found that these soluble and nanoparticle PAMAM materials can bind to both cell-free DNA and RNA released as a result of treating triple-negative breast cancer cells with chemotherapy drugs such as doxorubicin and paclitaxel. These PAMAM-G3 materials are termed as nucleic acid binding polymers and nucleic-acid binding polymeric nanoparticles.My thesis dissertation explores the anti-metastatic effects of nucleic-acid binding polymeric nanoparticles delivering the chemotherapy drug paclitaxel using in-vitro and in-vivo models. Two murine metastatic breast cancer models served as the basis for assessing the effects of conventional paclitaxel delivery compared to paclitaxel delivery from within PAMAM nucleic-acid binding polymeric nanoparticles with respect to primary tumor growth, extent of lung metastasis, and the systemic inflammatory response reflected in murine serum. Compared to treatment with unencapsulated paclitaxel, delivery of paclitaxel within the PAMAM nucleic-acid binding polymeric nanoparticles resulted in significantly decreased serum cell-free DNA levels, decreased inflammatory cytokines, and a lower degree of lung metastasis in the mice. The decrease in the degree of lung metastasis in mice receiving paclitaxel within the PAMAM nanoparticles was confirmed by assessing the photon flux signal of 4T1-luciferase breast cancer cells invading the murine lungs in both in-vivo and ex-vivo imaging and by using a machine learning method to quantify the degree of metastasis in H&E- stained sections of the lungs. The ability to mitigate the phenomenon of chemotherapy-induced cancer metastasis while effectively delivering the chemotherapy to the tumor microenvironment could help improve the outcomes of patients being treated with chemotherapy. This work developed a therapeutic cationic PAMAM nanocarrier-based strategy to inhibit paclitaxel-induced metastasis by scavenging cell-free nucleic acids and mitigating cell-free nucleic acid-induced inflammation.

Indiana University-Purdue University Indianapolis (IUPUI) / The DNA Base Excision Repair (BER) pathway repairs DNA damaged by endogenous and exogenous agents including chemotherapeutic agents. Removal of the damaged base by a DNA glycosylase creates an apurinic / apyrimidinic (AP) site. AP endonuclease1 (Ape1), a critical component in this pathway, hydrolyzes the phosphodiester backbone 5’ to the AP site to facilitate repair. Additionally, Ape1 also functions as a redox factor, known as Ref-1, to reduce and activate key transcription factors such as AP-1 (Fos/Jun), p53, HIF-1α and others. Elevated Ape1 levels in cancers are indicators of poor prognosis and chemotherapeutic resistance, and removal of Ape1 via methodology such as siRNA sensitizes cancer cell lines to chemotherapeutic agents. However, since Ape1 is a multifunctional protein, removing it from cells not only inhibits its DNA repair activity but also impairs its other functions. Our hypothesis is that a small molecule inhibitor of the DNA repair activity of Ape1 will help elucidate the importance (role) of its repair function in cancer progression as wells as tumor drug response and will also give us a pharmacological tool to enhance cancer cells’ sensitivity to chemotherapy. In order to discover an inhibitor of Ape1’s DNA repair function, a fluorescence-based high-throughput screening (HTS) assay was used to screen a library of drug-like compounds. Four distinct compounds (AR01, 02, 03 and 06) that inhibited Ape1’s DNA repair activity were identified. All four compounds inhibited the DNA repair activity of purified Ape1 protein and also inhibited Ape1’s activity in cellular extracts. Based on these and other in vitro studies, AR03 was utilized in cell culture-based assays to test our hypothesis that inhibition of the DNA repair activity of Ape1 would sensitize cancer cells to chemotherapeutic agents. The SF767 glioblastoma cell line was used in our assays as the chemotherapeutic agents used to treat gliobastomas induce lesions repaired by the BER pathway. AR03 is cytotoxic to SF767 glioblastoma cancer cells as a single agent and enhances the cytotoxicity of alkylating agents, which is consistent with Ape1’s inability to process the AP sites generated. I have identified a compound, which inhibits Ape1’s DNA repair activity and may have the potential in improving chemotherapeutic efficacy of selected chemotherapeutic agents as well as to help us understand better the role of Ape1’s repair function as opposed to its other functions in the cell.