Breast cancer, the most common malignancy diagnosed in women, is one of the leading causes of death in women worldwide. In South Africa only 32% of women diagnosed with advanced breast cancer survive more than five years. The search for new chemotherapeutic agents capable of effectively treating breast cancer is therefore essential. Recent evidence supporting the cancer stem cell theory of cancer development for breast cancer challenges the current theories of cancer development and hence treatment. Cancer stem cells are a small subpopulation of tumour cells that possess properties of both cancer cells and stem cells and are believed to be the tumour-initiating population of many cancers. Cancer stem cells are inherently resistant to many chemotherapeutic agents and in this way have been associated with repopulation of tumours after chemotherapy. This phenomenon is proposed as a possible mechanism for cancer relapse after treatment. Cancer stem cells have also been implicated in metastasis, the major cause of mortality in cancer patients. Therefore, any treatment that is capable of targeting and removing breast cancer stem cells may have the theoretical potential to effectively treat breast cancer. However, there are currently no such treatments available for clinical use. We were provided access to a library of novel indigenous small molecules isolated from red and brown algae found off the Eastern Cape of South Africa. The aim of this project was to analyse the anti-cancer and anti-cancer stem cell properties of the compounds in this library and to identify „hit‟ compounds which could form the basis for future development into new anti-cancer drugs. Ten novel compounds of algal origin were tested for cytotoxicity, by determining their ability to inhibit the growth of MCF12A breast epithelial cells and MCF7 breast cancer cells using the colorimetric MTT [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] cell proliferation assay. All but one of the compounds tested exhibited cytotoxicity towards the MCF7 cancer cell line, with IC50 values (the concentration of the compound that leads to a 50% inhibition in cell growth) of between 3 μM and 90 μM. The chemotherapeutic drug paclitaxel was used as a positive control. Four of the compounds (RUMB-001, RUMB-002, RUMB-007 and RUMB-010/saragaquinoic acid) were significantly more toxic to the MCF7 cancer cell line, than the „normal‟ MCF12A breast cells and were selected as priority compounds for further analyses. In addition, two other compounds were selected as priority compounds, one highly cytotoxic towards both MCF12A and MCF7 cell lines (RUMB-015) and one which was non toxic to either cell line (RUMB-017/018). Preliminary studies into the mechanism of cytotoxicity using Western blot analysis for poly (ADP-ribose) polymerase (PARP) cleavage and Hoechst 33342 immunostaining in MCF-7 cells were largely unsuccessful. The Hoechst 33342 immunostaining assay did provide tentative evidence that selected priority compounds were capable of inducing apoptosis, although these assays will need to be repeated using a less subjective assay to confirm the results. The priority compounds were subsequently investigated for their cytotoxic effect on the cancer stem cell-enriched side population in MCF7 cells. The ability of the priority compounds to selectively target the cancer stem cell containing side population was assessed using two complementary flow cytometry-based techniques – namely the Hoechst 33342-exclusion assay, and fluorescent immunostaining for the expression of the putative cancer stem cell marker, ABCG2+. The ABCG2+ staining assay was a novel technique developed during the course of this study. It remains to be fully validated, but it may provide a new and reliable way to identify and analyse cancer stem cell containing side population cells. The MCF7 cells were treated with the compounds and the proportion of putative cancer stem cells compared with the size of the population in untreated cells was assessed. Three compounds (RUMB-010, RUMB-015 and RUMB-017/018) capable of reducing the proportion of side population cells within the MCF7 cell line were identified. Taking these data together, we identified two potential „hit‟ compounds which should be prioritised for future research. These are compounds RUMB-010/sargaquinoic acid and RUMB-017/018. RUMB-010 is of interest as it was shown to target the putative cancer stem cell population, in addition to the bulk MCF7 tumour line, but was relatively less toxic to the „normal‟ MCF12A cell line. RUMB-017/018 is of interest due to the ability to selectively target the cancer stem cell enriched side population, while having little effect on the normal (MCF12A) or bulk tumour (MCF7) cell lines tested. These compounds will be important as „hit‟ compounds for drug development and as tool compounds to study cancer and cancer stem cell biology.

Thesis (Ph.D. (Biochemistry)) -- University of Limpopo, 2021 / Breast cancer is the leading cause of female deaths in the world. Varying types of therapy options are available, yet these conventional treatments for the malignancy are known to have numerous side effects. Similar to other diseases, herbal remedies are being explored as alternative treatment options as well as starting points for development of new drugs to treat breast cancer. Bidens pilosa is a weed distributed throughout the world with known medicinal properties. Its anti-cancer activity has been established in various cancers. This study aimed to investigate the epigenetic patterns affected by a bioactive extract of B. pilosa in breast cancer. A crude methanol extract of B. pilosa was fractionated with n-hexane, chloroform, ethyl acetate, n-butanol, 65% methanol and water. Healing properties of plants are often an attribute of the presence of phenolic compounds within the plant and the sub-fractions of the methanol extract of B. pilosa were, therefore, assayed for these compounds. The water sub-fraction showed the highest content of total phenolic compounds, however, when the sub-fractions were analysed for the presence of two classes of specific phenolic compounds, the butanol sub-fraction boasted the highest concentration of flavonoids and tannins, affording it superior antioxidant activity in a quantitative DPPH assay. Distribution of the antioxidant compounds in TLC-DPPH analysis also supported this finding. Despite its high antioxidant compound content, cytotoxicity of the butanol sub-fraction in MCF-7 breast cancer cells was not impressive in the MTT viability assay. Treatment with varying concentrations of the chloroform sub-fraction resulted in a better dose- and time-dependent decrease in cell viability of MCF-7 cells than all the other sub-fractions as well as the crude methanol extract. Analysis of breast cancer genes affected by the chloroform sub-fraction on the Human Breast Cancer RT2 Profiler PCR array showed repression in BRCA1 and BRCA2, genes classified as tumour suppressors. Bisulfite pyrosequencing showed no significant modification in methylation of selected CpG islands within the promoter regions of both genes. Results of the array also showed decreased expression of CDH1 which is associated with invasiveness and aggression of tumours. Its investigated CpG island was also shown not to be differentially methylated by treatment of the cells with the chloroform sub-fraction of the extract. As a well-appreciated biomarker for breast cancer risk, BRCA1 protein expression was further investigated. Western blot analysis showed parallel findings to those of the PCR array, with down-regulation of BRCA1 within 24 hours of treatment of MCF-7 cells with the sub-fraction. Repression of the BRCA genes is strongly linked to arrest of cells at the G2/M phase of the cell division cycle, and this was therefore also assessed. Treatment of MCF-7 cells with the chloroform sub-fraction effected a dose-dependent accumulation of cells at the G2/M phase of the cell cycle as determined by flow cytometry. Results of global DNA methylation analysis showed an increase in chromosomal instability by a significantly reduced level of methylation of the genome. This hypomethylation also supports arrest of the cells at the G2/M phase of the cell cycle, as cells accumulate at this checkpoint, awaiting repair to prevent segregation of broken chromosomes during mitosis. However, the lack of BRCA1 suggests that repair proteins were not recruited to the sites of repair and the cells were consequently directed to apoptosis. Analysis of the effect of the chloroform sub-fraction of the methanol extract of B. pilosa in the Mitopotential assay showed an increase in the number of dead cells with depolarised mitochondrial membranes, alluding to the intrinsic mode of apoptotic cell death in MCF-7 cells treated with the sub-fraction. Down-regulation of BRCA1 is further associated with telomerase inactivation in cancer cells. Treatment of MCF-7 cells with the chloroform sub-fraction reduced telomerase activity within 24 hours of treatment, with an absence of activity following treatment with 100 and 125 μg/ml of the sub-fraction. This lack of telomerase activity resulted in shortened telomeres which limit proliferative ability of the cells. Characterisation of the six sub-fractions of the methanol extract of B. pilosa with GC-MS showed an abundance of fatty acids in the chloroform sub-fraction, specifically α-linolenic acid, palmitic acid and linoleic acid. Palmitic acid is alleged to play a role in down-regulation of BRCA1 and its abundance in this sub-fraction leads to the conclusion that palmitic acid may be responsible for the decreased expression of BRCA1 in MCF-7 breast cancer cells. The down-regulation results in hypomethylation of the genome leading to cell cycle arrest at the G2/M checkpoint and subsequent apoptosis as a result of this repression of BRCA1. Repression of BRCA1 also leads to inactivation of telomerase, inhibiting cell proliferation. Taken together, the observed antioxidant activity and pro-apoptotic potential attributed to epigenetic modifications validate B. pilosa as an anticancer agent. Our findings merit the plant for use in development of potential breast cancer drugs. / SAMRC and University of Limpopo (UL)

Thesis (M. A. (Nursing Science)) -- University of Limpopo, 2021 / Background: Mastectomy is one of the treatments for breast cancer. It causes a change in the appearance of the breast thus causing a major effect on women’s self‑image and a decreased sense of femininity that can lead to anxiety and depression to such an extent that they avoid visiting public places. The study explored and described experiences of women who had undergone mastectomy at Mankweng Hospital, Limpopo Province, South Africa. Study design: This study used a phenomenological approach to perform a qualitative, exploratory, descriptive, and contextual research. Using a non-probability purposive sample of about 15 women who had undergone mastectomy in Mankweng hospital. Data were gathered through semi-structured interviews. The semi-structured interviews' audio recordings were transcribed verbatim. Seven steps procedure for data analysis using Colaizzi method was used to interpret the data. Results: The most challenging experience by women who had undergone mastectomy defined as a feeling of being disabled, anxious, relieved, acceptance, and financial constraints. Conclusion: Strategies to address the challenges faced by women who had undergone mastectomy has been developed to assist them with coping mechanism post mastectomy and living a normal life. Key concepts: Breast Cancer, Mastectomy, Women

Breast cancer affects over three million women in the United States, but this disease burden is not shared equally across all races. Black women, in particular, are diagnosed with more advanced cancer at a younger age and experience a disproportionately high mortality rate compared to white women. Factors that contribute to such disparity include socioeconomic status, tumor biology, age, insurance status, comorbidities, obesity, patients’ reproductive history and barriers to quality care. These factors alone, however, do not account for all the racial differences in mortality and outcomes experienced by black women. There is a growing body of literature that indicates black women are not receiving the same treatment and care as white women. Black women are less likely to receive surgery, radiation therapy, hormone therapy and targeted therapy than white women. Black women are also more likely to experience delays in the initiation of treatment, early discontinuation of treatment and overall guideline non-concordant care. The current literature has presented widespread racial disparities in the treatment of black women with breast cancer. Future research needs to focus on tangible interventions such as physician bias training and patient navigators to mitigate the inequity of care in the treatment of breast cancer.

Indiana University-Purdue University Indianapolis (IUPUI) / Breast cancer is the second most common cancer among women in the US after skin cancer. While early detection and improved therapy has led to an overall decline in breast cancer mortality, metastatic disease remains largely incurable, indicating a need for improved therapeutic options for patients. Telomeres are repetitive (TTAGGG)n DNA sequences found at the end of chromosomes that protect the ends from recombination, end to end fusions, and recognition as damaged DNA. The enzyme telomerase acts to stabilize short telomeres, preventing apoptosis or senescence due to genomic instability. Telomerase is active in 85-90% of cancers, and inactive in most normal cells, making telomerase an attractive target for cancer therapy. Use of the telomerase-specific, lipidated oligonucleotide GRN163L can antagonize telomerase activity and telomere maintenance in cancer cells by preventing telomerase from binding to telomeres. GRN163L has been shown by our laboratory to inhibit breast cancer cell growth and metastasis in animal models. However, the mechanisms of cancer cell growth and metastatic inhibition via GRN163L are not completely understood. The overall goal of this research project was to further elucidate the role of telomerase in breast cancer cell survival by: 1) determining the effects of combining telomere dysfunction induced by GRN163L with a DNA damage inducer (irradiation); 2) elucidating the mechanisms underlying the cellular response to GRN163L and the effect of combination therapy with the mitotic inhibitor paclitaxel; and 3) testing the hypothesis that a telomerase inhibitor can augment the effects of trastuzumab in breast cancer cells with HER2 amplification. Results support the central hypothesis that the telomere dysfunction, structural and proliferative changes in breast cancer cells induced by GRN163L can synergize with irradiation, paclitaxel, and trastuzumab to inhibit the tumorigenicity of breast cancer cells both in vitro and in vivo. Furthermore, GRN163L can restore sensitivity of therapeutically resistant breast cancer cells to trastuzumab. These results provide insight into the role of telomerase in cancer cell growth. Additionally, implications of this research support GRN163L as an important part of therapeutic regimens for primary tumors, recurrence, and metastatic disease.

Indiana University-Purdue University Indianapolis (IUPUI) / Hispanics are more likely to die from breast cancer compared to non - Hispanic whites matched on stage and age at diagnosis. Higher mortality rates among Hispanics are attributed to cancer - related disparities across the cancer continuum including later - stage detection. While research has shown that socioeconomic factors play a significant role in the development and maintenance of cancer - related disparities, differences persist when these factors are controlled. Thus far, research on cultural factors and cognitions surrounding cancer is limited. The current study investigated illness representations of cancer and their determinants among Hispanic men and women (N = 120) using a cross - sectional survey approach. The study sample was comprised of predominantly first generation, employed Hispanic women in their early - thirties from Mexico. Most had not resided in the U.S. for more than 5 - 9 years. Half of the sample reported an annual income of $20,001 - $30,000 and completing at least a middle school education. While the majority indicated that they did not have health insurance, most indicated that they did have a regular source of health care. Additionally, while most had not been diagnosed with cancer, nearly half of the sample knew of someone diagnosed with cancer. Descriptive data regarding illness identity, illness coherence, timeline, causes, consequences, and controllability are provided. Results suggest that demographic factors (i.e. acculturation, education, and income), cultural constructs (i.e. fatalism and familism), intrapersonal factors (state and trait anxiety), and previous experience with cancer were associated with illness representations of breast cancer. The study adds to theliterature by systematically investigate illness representations of breast cancer and their determinants among a diverse sample of Hispanic men and women. This is a significant first step that can be used to guide and develop effective and culturally appropriate interventions that ultimately reduce disparities across the cancer continuum.

With the increasing number of breast cancer survivors, there is a need to enhance health education to help survivors make informed decisions about maximizing their quality of life. YouTube is one of the most popular video applications that can be used for public health education. Nonetheless, there is little research on the content of health-related information that is uploaded to YouTube relevant to breast cancer survivors. This study was intended to help fill that gap in knowledge by describing the sources, formats, and content conveyed in the most widely viewed YouTube videos on breast cancer. YouTube was searched with a cleared browsing history using the key search term “breast cancer.” The resulting videos were sorted by view count. Videos were then screened for inclusion and exclusion criteria, yielding a sample of 100 videos with the most views. Video title, link, number of views, and date of upload were coded along with content included in each video. The inter- and intra-rater reliability was acceptable (Kappa’s = .79 and .97, respectively). The sample of 100 videos was collectively viewed 135,311,626 times, suggesting that the subject of breast cancer is a popular topic on YouTube. Nearly half of the sample videos (n = 45) were uploaded by television news/media agencies. Combined/multiple formats were the most popular format (n = 61), followed by still images/text (n = 48). General information on cancer was found to be the most common (n = 71), followed by screening for breast cancer occurrence/ recurrence (n = 62), and cancer treatments/breast cancer treatments (n = 45). Several of the content categories were rarely covered in the most-watched videos—for example, cancer rehabilitation recommendations, returning to work after cancer treatment, and financial burden/management of cancer. Thus, while topics such as breast cancer screening are widely covered, topics for breast cancer survivors regarding maximizing their quality of life are less widely covered. Few videos (n = 3) contained misinformation, but these videos were viewed millions of times, emphasizing the need for ongoing monitoring to identify and remove misinformation. The findings of this study indicated that YouTube videos on breast cancer gained over 135 million views. YouTube can be a great media channel for public health education. Nonetheless, there is significant need for more high-quality YouTube videos to be created to help breast cancer survivors navigate their cancer journey.

Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2021 / Breast cancer is a malignant tumour that starts in the cells of the breast. Many studies revealed aromatase (CYP19A1) and cyclin-dependent kinase 2 (CDK2) as possible therapeutic targets regarding breast cancer treatment, because they play crucial roles in anti-apoptotic processes during cell proliferation. Quinoxaline derivatives have attracted a great deal of attention due to their biological activities against fungi, virus, bacteria and cancer. Computer modelling was employed in order to reduce time and cost by searching the library of molecules and identifying those which are likely to bind to the drug target. A library of new one hundred (100) nitro and amino quinoxaline alkyne derivatives were successfully designed and screened against target proteins (CYP19A1 and CDK2) using virtual screening technique and thirteen (13) molecules were identified to be hit compounds against both targets with the docking score ranging from -6.143 to -8.372 kcal/mol as a measure of binding affinity. The hit compounds were subjected to IFD in order to identify tight binding through intermolecular interactions with active site residues of the binding pocket of the target proteins. All identified nitro and amino quinoxaline alkyne derivatives were successfully synthesised in a multi-step reaction sequence and their spectroscopic analysis (NMR, FTIR and MS) were in good agreement with the proposed structures in a good to moderate yield. The newly synthesised novel amino and nitro-quinoxaline derivatives were evaluated for anti-proliferative activity against breast cancer (MCF-7). Compound 59 showed to possess good inhibition against MCF-7 with an IC50 of 9.102 μM, whereas compounds 34, 54, 56 and 61 showed promising activity against MCF-7 with an IC50 value of < 50 μM. However, the MTT assay results showed that 59 was found to be toxic with an IC50 value of 0.205 μM against Raw 264.7 cell line. The dose response investigations showed that 31 and 34 have the promising anti-cancer activity against CYP19A and the correlation between molecular modelling (in-silico) and CYP19A inhibition activities (in- vitro), was established as compounds 31 and 34 were identified to bind to the drug target (CYP19A) with the docking score of -8.372 and 7.630 kcal/mol respectively. All the synthesized compounds were evaluated for the antitubercular activity against Mtb H37Rv strain as a secondary study. Compounds 57-62 with nitro-quinoxaline derivatives exhibited stronger inhibitory effects on Mtb H37Rv strain. In addition, compounds 60 and 62 were found to be most active against Mtb H37Rv with the high activity at MIC90 of <0.65 and <0.64 μM respectively. All active compounds are currently investigated for their cytotoxicity which have not been investigated before. / National Research Foundation (NRF) and Sasol Inzalo Foundation

Male breast cancer (MBC) is rare, and research on the predictors of MBC has been limited because of inadequate funding in and outside of the United States. One goal of this study was to eradicate the stereotyping of breast cancer as a female disease. The emergence of medical technology and education to benefit the public will help to ensure greater health awareness at the individual, community, and global levels. The purpose of this study was to understand the influence of the predictors of age; race (Black, White, and Other); and grade of cancer (I, II, or III) on the outcome of mastectomy in MBC. The study was guided by the social determinants of health model. A quantitative approach was used to analyze archival data from 2011 to 2013 in the Surveillance Epidemiology and End Results (SEER) database using SPSS v.23. Data from 427 MBC patients ages 18 years and older from the United States comprised the sample. The SEER data were analyzed using logistic regression analysis. Results showed that of the 427 cases of MBC that were analyzed, 55 had a diagnosis of Grade I, 190 had a diagnosis of Grade II, and 182 had a diagnosis of Grade III. For 3 years, 116 men had undergone mastectomy. Grade I cancer, Grade II cancer, and Grade III cancer were statistically insignificant predictors of mastectomy; however, age, race was a statistically significant predictor of mastectomy among White men with MBC. The results will contribute to social change initiatives by educating the public about the predictors of mastectomy in MBC patients. The results also will increase the current knowledge base by informing the public, clinical professionals, and patients about the relationship of the predictors of age; race; and grade of cancer (I, II, or III) on the outcome of mastectomy in MBC.

The purpose of the present study was to examine the role that specific factors play in the quality of life (QL) for women with recurrent breast cancer.