INTRODUÇÃO: No mundo ocidental, a prevalência de adenocarcinoma da junção esofagogástrica vem crescendo nas últimas décadas. Atualmente, é aceito que o adenocarcinoma do esôfago se desenvolve de uma lesão pré-maligna: esôfago de Barrett. Este carcinoma é de difícil diagnóstico nos seus estágios iniciais, o que resulta em uma mortalidade significativa. O estudo da biologia molecular tem demonstrado que grande parte dos tumores malignos tem origem na interação entre o componente hereditário e influências externas, que em indivíduos predispostos podem ocasionar alterações genéticas que influenciem o controle da diferenciação e crescimento celular. O p21 (WAF1/CIP1) tem um papel fundamental na regulação do ciclo celular, e sua expressão imunoistoquímica tem sido estudada em diversos tumores, mostrando influência no prognóstico de várias neoplasias. OBJETIVO: Verificar a prevalência da expressão da proteína p21 em pacientes com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METODOLOGIA: A população em estudo foi constituída de 42 pacientes com adenocarcinoma de esôfago diagnosticados no GCEE/HCPA entre janeiro de 1998 e dezembro de 2002. A expressão da proteína p21 foi realizada por meio de imunoistoquímica, com anticorpo primário, p21, clone SX118, código M7202 da DAKO, e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system – IRS). RESULTADOS: Foram estudados 42 pacientes. 83,3% eram do sexo masculino, com idade superior a 40 anos. Destes, 56,2% foram submetidos a procedimentos cirúrgicos com intenção curativa: Gastrectomia total e Esofagogastrectomia transiatal. Os demais foram submetidos à cirurgia paliativa ou não sofreram tratamento cirúrgico. Apenas cinco pacientes receberam tratamento adjuvante com quimioterapia e radioterapia, isoladas ou combinadas. Quanto ao estadiamento, 78,6% dos pacientes apresentavam doença avançada, estádios III e IV. Apenas 9 apresentaram positividade para o p21, quando considerado o Sistema de Escore de Imunorreatividade (em que p21+ é ³ 3). CONCLUSÃO: A proteína p21 esteve expressa em 9 dos 42 pacientes (21,4%) com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre. Nessa casuística, o acúmulo de p21 não se mostrou essencial no processo de carcinogênese do adenocarcinoma esofágico. / INTRODUCTION: In western societies, the prevalence of adenocarcinoma of the gastroesophageal junction has increased in recent years. It is commonly accepted today that esophageal adenocarcinoma develops from a premalignant lesion: Barrett’s esophagus. This type of carcinoma is hardly diagnosed at early stages, which results in significant mortality. Molecular biology studies have shown that most malignant tumors originate from the interaction between inherited characteristics and external factors, which may cause genetic changes that interfere with the control over the differentiation and growth of cells in susceptible individuals. p21 (WAF1/CIP1) has a key role in the regulation of the cell cycle, and its immunohistochemical expression has been investigated in several tumors, showing that it influences the prognosis of various neoplasms. OBJECTIVE: To check the prevalence of p21 protein expression in patients with esophageal adenocarcinoma diagnosed in the last five years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METHODS: The study population consisted of 42 patients with esophageal adenocarcinoma diagnosed by the GCEE/HCPA between January 1998 and December 2002. The expression of p21 protein was determined by immunohistochemistry using primary antibody, p21, clone SX118, code M7202 (Dako), and assessed according to the Immunoreactive scoring system (IRS). RESULTS: Of 42 analyzed patients, 83.3% were male and older than 40 years. Among these, 56.2% were submitted to curative resection: total gastrectomy and transhiatal esophagogastrectomy. The remaining patients were submitted to palliative surgery or did not undergo any surgical treatment. Only five patients received adjuvant chemotherapy and radiation therapy, either alone or combined. Advanced disease (stages III and IV) was detected in 78.6% of the patients. Only nine patients were positive for p21, according to the immunoreactive scoring system (p21+ ³ 3). CONCLUSION: p21 was expressed in 9 of 42 patients (21.4%) with esophageal adenocarcinoma diagnosed in the last five years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre. In our patient population, the accumulation of p21 did not play a key role in the carcinogenesis of esophageal adenocarcinoma.

INTRODUÇÃO: No mundo ocidental, a prevalência de adenocarcinoma da junção esofagogástrica vem crescendo nas últimas décadas. Atualmente, é aceito que o adenocarcinoma do esôfago se desenvolve de uma lesão pré-maligna: esôfago de Barrett. Este carcinoma é de difícil diagnóstico nos seus estágios iniciais, o que resulta em uma mortalidade significativa. O estudo da biologia molecular tem demonstrado que grande parte dos tumores malignos tem origem na interação entre o componente hereditário e influências externas, que em indivíduos predispostos podem ocasionar alterações genéticas que influenciem o controle da diferenciação e crescimento celular. O p21 (WAF1/CIP1) tem um papel fundamental na regulação do ciclo celular, e sua expressão imunoistoquímica tem sido estudada em diversos tumores, mostrando influência no prognóstico de várias neoplasias. OBJETIVO: Verificar a prevalência da expressão da proteína p21 em pacientes com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METODOLOGIA: A população em estudo foi constituída de 42 pacientes com adenocarcinoma de esôfago diagnosticados no GCEE/HCPA entre janeiro de 1998 e dezembro de 2002. A expressão da proteína p21 foi realizada por meio de imunoistoquímica, com anticorpo primário, p21, clone SX118, código M7202 da DAKO, e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system – IRS). RESULTADOS: Foram estudados 42 pacientes. 83,3% eram do sexo masculino, com idade superior a 40 anos. Destes, 56,2% foram submetidos a procedimentos cirúrgicos com intenção curativa: Gastrectomia total e Esofagogastrectomia transiatal. Os demais foram submetidos à cirurgia paliativa ou não sofreram tratamento cirúrgico. Apenas cinco pacientes receberam tratamento adjuvante com quimioterapia e radioterapia, isoladas ou combinadas. Quanto ao estadiamento, 78,6% dos pacientes apresentavam doença avançada, estádios III e IV. Apenas 9 apresentaram positividade para o p21, quando considerado o Sistema de Escore de Imunorreatividade (em que p21+ é ³ 3). CONCLUSÃO: A proteína p21 esteve expressa em 9 dos 42 pacientes (21,4%) com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre. Nessa casuística, o acúmulo de p21 não se mostrou essencial no processo de carcinogênese do adenocarcinoma esofágico. / INTRODUCTION: In western societies, the prevalence of adenocarcinoma of the gastroesophageal junction has increased in recent years. It is commonly accepted today that esophageal adenocarcinoma develops from a premalignant lesion: Barrett’s esophagus. This type of carcinoma is hardly diagnosed at early stages, which results in significant mortality. Molecular biology studies have shown that most malignant tumors originate from the interaction between inherited characteristics and external factors, which may cause genetic changes that interfere with the control over the differentiation and growth of cells in susceptible individuals. p21 (WAF1/CIP1) has a key role in the regulation of the cell cycle, and its immunohistochemical expression has been investigated in several tumors, showing that it influences the prognosis of various neoplasms. OBJECTIVE: To check the prevalence of p21 protein expression in patients with esophageal adenocarcinoma diagnosed in the last five years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METHODS: The study population consisted of 42 patients with esophageal adenocarcinoma diagnosed by the GCEE/HCPA between January 1998 and December 2002. The expression of p21 protein was determined by immunohistochemistry using primary antibody, p21, clone SX118, code M7202 (Dako), and assessed according to the Immunoreactive scoring system (IRS). RESULTS: Of 42 analyzed patients, 83.3% were male and older than 40 years. Among these, 56.2% were submitted to curative resection: total gastrectomy and transhiatal esophagogastrectomy. The remaining patients were submitted to palliative surgery or did not undergo any surgical treatment. Only five patients received adjuvant chemotherapy and radiation therapy, either alone or combined. Advanced disease (stages III and IV) was detected in 78.6% of the patients. Only nine patients were positive for p21, according to the immunoreactive scoring system (p21+ ³ 3). CONCLUSION: p21 was expressed in 9 of 42 patients (21.4%) with esophageal adenocarcinoma diagnosed in the last five years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre. In our patient population, the accumulation of p21 did not play a key role in the carcinogenesis of esophageal adenocarcinoma.

INTRODUÇÃO: No mundo ocidental, a prevalência de adenocarcinoma da junção esofagogástrica vem crescendo nas últimas décadas. Atualmente, é aceito que o adenocarcinoma do esôfago se desenvolve de uma lesão pré-maligna: esôfago de Barrett. Este carcinoma é de difícil diagnóstico nos seus estágios iniciais, o que resulta em uma mortalidade significativa. O estudo da biologia molecular tem demonstrado que grande parte dos tumores malignos tem origem na interação entre o componente hereditário e influências externas, que em indivíduos predispostos podem ocasionar alterações genéticas que influenciem o controle da diferenciação e crescimento celular. O p21 (WAF1/CIP1) tem um papel fundamental na regulação do ciclo celular, e sua expressão imunoistoquímica tem sido estudada em diversos tumores, mostrando influência no prognóstico de várias neoplasias. OBJETIVO: Verificar a prevalência da expressão da proteína p21 em pacientes com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METODOLOGIA: A população em estudo foi constituída de 42 pacientes com adenocarcinoma de esôfago diagnosticados no GCEE/HCPA entre janeiro de 1998 e dezembro de 2002. A expressão da proteína p21 foi realizada por meio de imunoistoquímica, com anticorpo primário, p21, clone SX118, código M7202 da DAKO, e avaliada de acordo com o Sistema de Escore de Imunorreatividade (Immunoreactive scoring system – IRS). RESULTADOS: Foram estudados 42 pacientes. 83,3% eram do sexo masculino, com idade superior a 40 anos. Destes, 56,2% foram submetidos a procedimentos cirúrgicos com intenção curativa: Gastrectomia total e Esofagogastrectomia transiatal. Os demais foram submetidos à cirurgia paliativa ou não sofreram tratamento cirúrgico. Apenas cinco pacientes receberam tratamento adjuvante com quimioterapia e radioterapia, isoladas ou combinadas. Quanto ao estadiamento, 78,6% dos pacientes apresentavam doença avançada, estádios III e IV. Apenas 9 apresentaram positividade para o p21, quando considerado o Sistema de Escore de Imunorreatividade (em que p21+ é ³ 3). CONCLUSÃO: A proteína p21 esteve expressa em 9 dos 42 pacientes (21,4%) com adenocarcinoma de esôfago diagnosticados nos últimos cinco anos no Grupo de Cirurgia de Esôfago e Estômago do Hospital de Clínicas de Porto Alegre. Nessa casuística, o acúmulo de p21 não se mostrou essencial no processo de carcinogênese do adenocarcinoma esofágico. / INTRODUCTION: In western societies, the prevalence of adenocarcinoma of the gastroesophageal junction has increased in recent years. It is commonly accepted today that esophageal adenocarcinoma develops from a premalignant lesion: Barrett’s esophagus. This type of carcinoma is hardly diagnosed at early stages, which results in significant mortality. Molecular biology studies have shown that most malignant tumors originate from the interaction between inherited characteristics and external factors, which may cause genetic changes that interfere with the control over the differentiation and growth of cells in susceptible individuals. p21 (WAF1/CIP1) has a key role in the regulation of the cell cycle, and its immunohistochemical expression has been investigated in several tumors, showing that it influences the prognosis of various neoplasms. OBJECTIVE: To check the prevalence of p21 protein expression in patients with esophageal adenocarcinoma diagnosed in the last five years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre (GCEE/HCPA). METHODS: The study population consisted of 42 patients with esophageal adenocarcinoma diagnosed by the GCEE/HCPA between January 1998 and December 2002. The expression of p21 protein was determined by immunohistochemistry using primary antibody, p21, clone SX118, code M7202 (Dako), and assessed according to the Immunoreactive scoring system (IRS). RESULTS: Of 42 analyzed patients, 83.3% were male and older than 40 years. Among these, 56.2% were submitted to curative resection: total gastrectomy and transhiatal esophagogastrectomy. The remaining patients were submitted to palliative surgery or did not undergo any surgical treatment. Only five patients received adjuvant chemotherapy and radiation therapy, either alone or combined. Advanced disease (stages III and IV) was detected in 78.6% of the patients. Only nine patients were positive for p21, according to the immunoreactive scoring system (p21+ ³ 3). CONCLUSION: p21 was expressed in 9 of 42 patients (21.4%) with esophageal adenocarcinoma diagnosed in the last five years by the Group for Surgeries of the Esophagus and Stomach of Hospital de Clínicas de Porto Alegre. In our patient population, the accumulation of p21 did not play a key role in the carcinogenesis of esophageal adenocarcinoma.

No description available.

NAMPT (Nicotinamide phosphoribosyltransferase) catalyses the rate-limiting step in the NAD biosynthesis from nicotinamide and thereby regulates the activity of NAD-dependent enzymes. Cancer cells are highly dependent on NAD for energy and DNA repair processes and are assumed to be more susceptible to an inhibition of NAD synthesis than non-transformed cells. We aimed to investigate whether or not inhibition of NAMPT with its specific inhibitor FK866 can sensitize leukemia cells for chemotherapeutic agents. NAMPT protein abundance, enzymatic activity and NAD concentrations were significantly higher in Jurkat and Molt-4 leukemia cell lines compared to normal peripheral blood mononuclear cells. Combination of etoposide and FK866 caused increased cell death in leukemia cell lines compared to etoposide alone. Etoposide decreased protein abundance of NAD-dependent deacetylases SIRTUIN1. After combining etoposide and FK866 treatment SIRTUIN2 was further decreased and accumulation and acetylation of the downstream target p53 was further enhanced in MOLT4 cells. Concomitantly, protein abundance of p21 and cleaved BAX was increased. Targeting NAMPT could be a novel therapeutic strategy to enhance the efficacy of chemotherapeutic agents such as etoposide against leukemia.

Pancreatic ductal adenocarcinoma (PDAC), the most common form of pancreatic cancer, develops through progression of premalignant pancreatic intraepithelial neoplasias (PanINs). In mouse-models, KRAS-activation in acinar cells induced an acinar-to-ductal metaplasia (ADM), and mutation of the Kras oncogene is believed to initiate PanIN formation. ADM is also promoted by pancreatic injury, which cooperates with activated KRAS to stimulate PanIN and PDAC formation from metaplastic ducts. Our lab, and others, have shown that the downstream PI3K/AKT pathway is important for KRAS-mediated proliferation and survival in vitro and in vivo. Prior studies have demonstrated that full activation of AKT requires both PDK1- mediated phosphorylation of AKTT308 and mTOR complex 2 (mTORC2)-mediated phosphorylation of AKTS473. Given the importance of the PI3K/AKT signaling axis, I hypothesized that mTORC2 is required for KRAS-driven pancreatic tumorigenesis and investigated this relationship in mice by combining pancreasspecific expression of an activated KRASG12D molecule with deletion of the essential mTORC2 subunit RICTOR. In the context of activated KRAS, Rictor-null pancreata developed fewer PanIN lesions; these lesions lacked mTORC2 signaling and their proliferation and progression were impaired. Higher levels of nuclear cyclin dependent kinase inhibitors (CDKIs) were maintained in Rictor-null lesions, and nuclear BMI1, a known regulator of the CDKI Cdkn2a, inversely correlated with their expression.Rictor was not required for KRAS-driven ADM following acute pancreatitis, however the inverse correlation between CDKIs and BMI1 was maintained in this system. Treatment of PDX-Cre;KRASG12D/+;Trp53R172H/+ mice with an mTORC1/2 inhibitor delayed tumor formation, and prolonged the survival of mice with late stage PDAC. Knockdown of Rictor in established PDAC cell lines impaired proliferation and anchorage independent growth supporting a role for mTORC2 in fully transformed cells. These data suggest that mTORC2 cooperates with activated KRAS in the initiation and progression of PanIN lesions and is required for the transformation and maintenance of PDAC. My work illustrates phenotypic differences between pancreatic loss of Rictor and PDK1 in the context of KRAS, broadens our understanding of this signaling node and suggests that mTORC2 may potentially be a viable target for PDAC therapies.

Indiana University-Purdue University Indianapolis (IUPUI) / The MDM2-p53 feedback loop is a well-characterized pathway. p53 is a transcription factor and regulates the transcriptional expression of genes that encode proteins responsible for cellular senescence, cell cycle arrest, apoptosis, and DNA repair. Various cellular stresses can result in p53 activation, including hypoxia, DNA damage by agents such as UV or IR, oncogenic signaling, nucleotide depletion and nucleolar stress from perturbation of ribosomal biogenesis. Under normal conditions, MDM2’s role in the pathway is to inhibit p53 function by directly binding to this protein and facilitating its ubiquitylation and 26S proteasome-mediated degradation. Under stressful cellular conditions, certain proteins interact with and rescue MDM2’s inhibition of p53. For example, upon exposure to small amounts of Actinomycin D, rRNA transcript synthesis is stalled resulting in the release of various ribosomal proteins including RPL5, RPL11 and RPL23; each of which has been shown to bind MDM2 within its central acidic domain and inhibit its ability to destabilize p53. Although the RPL5 binding region of MDM2 have been mapped in prior investigations, the MDM2-binding region(s) of RPL5 have yet to be characterized. By employing RPL5 deletion mutagenesis and in vitro GST-fusion protein-protein association assays with purified proteins, this dissertation attempts to elucidate those regions of RPL5 that may interact with MDM2. Normalizing RPL5-WT to 1.00, our study reveals that the basic N and C-terminals of RPL5 appear to bind with MDM2 while RPL5’s central region displays negligible binding to the central acidic domain of MDM2. Also, the possible meanings of these RPL5 MDM2 binding domains are discussed along with their utilization in potential future applications.

Indiana University-Purdue University Indianapolis (IUPUI) / Neurofibromatosis type 1 (NF1) is a neurocutaneous disorder that affects roughly 1 in 3500 individuals. In addition to physical features (e.g., neurofibromas), developmental disorders are also common that can affect cognition, learning, attention and social function. The NF1 gene encodes neurofibromin, a GTPase activating protein (GAP)-like protein that negatively regulates Ras GTPase activation. Mutation at the NF1 locus increases the output of MAPK and PI3K signal transduction from the cellular membrane to the nucleus. Similar to humans, Nf1+/- mice show spatial learning abnormalities that are potentially correlated with increases in GABA-mediated inhibition and deficits in long-term potentiation in the hippocampus. Here, we demonstrate for the first time that Nf1+/- mice exhibit a selective loss of long-term social learning / memory and increased GABAergic inhibition in the basolateral amygdala, a critical brain region for regulating social behaviors. Next, utilizing a genetic intercross, we show that the co-deletion of p21-activated kinase type 1 (Pak1-/-), which positively regulates MAPK activation, restores Nf1+/--dependent MAPK hyperactivation in neurons cultured from the frontal cortex. We found that the co-deletion of Pak1 in Nf1+/- mice (Nf1+/- / Pak1-/-) also restores the deficits in long-term social learning / memory seen in Nf1+/- mice and normalizes the increases in GABA-mediated inhibition in the BLA, as compared to Nf1+/- mice. Together, these findings establish a role for Nf1 and Pak1 genes in the regulation of social learning in Nf1-deficient mice. Furthermore, proteomic studies identify dysregulation of F-actin and microtubule dynamics in the prefrontal cortex, and implicate proteins associated with vesicular release as well as neurite formation and outgrowth (e.g., LSAMP, STXBP1, DREB). In the BLA, disintegrin and metalloproteinase domain-containing protein 22 (ADAM22) was identified, and ADAM22 may play a role in the regulation of AMPA receptors. Finally, due to the increased co-occurrence of NF1 and autism, these findings may also have important implications for the pathology and treatment of NF1-related social deficits and some forms of autism.

Le carcinome ovarien est l'une des tumeurs gynécologiques les plus meurtrières dans le monde et particulièrement au Canada. En effet, il s’agit du troisième cancer de l’appareil reproducteur féminin le plus fréquent au Canada, selon la Société Canadienne du Cancer qui estima que sur 3 000 canadiennes ayant été diagnostiquées avec un cancer de l’ovaire en 2022, environ 1 950 ne survivront pas à la maladie. Les traitements de première ligne pour ce cancer comprennent la chirurgie cytoréductive associée à une chimiothérapie à base de platine et de taxane comme l’association des anticancéreux que sont le Carboplatine et Paclitaxel. Nous retrouvons également comme traitement la radiothérapie, et, plus récemment, les inhibiteurs de la poly (ADP-ribose) polymérase (PARPi) comme l'Olaparib qui sont désormais utilisés en première ligne dans ce type de cancer. Ces traitements peuvent entraîner différentes décisions concernant le devenir des cellules, impliquant non seulement la mortalité ou la survie des cellules cancéreuses, mais aussi un arrêt de la prolifération induit par le traitement appelé TIS pour sénescence induite par la thérapie. Alors que les décisions relatives au devenir des cellules sont déterminantes pour l'issue du traitement du cancer, notre capacité à mesurer le devenir des cellules dans le cancer en temps réel est extrêmement limitée. Pour cette raison, il n'existe pas de modèles de cancer de l'ovaire qui puissent fournir un suivi non invasif du devenir des cellules à des moments spécifiques avec des biomarqueurs adaptés, pour décrypter le rôle des différents devenirs cellulaires, ou pour servir de contrôles expérimentaux précis dans les tests précliniques des stratégies d'intervention basées sur le devenir des cellules. Néanmoins, nous avons démontré qu’un fragment du promoteur du gène de la protéine p21, que nous avons nommé p21SEN, n'est exprimé que pendant la sénescence induite par les radiations, la chimiothérapie et les PARPi dans des lignées d’adénocarcinome ovarien à cellules claires (TOV21G). En effet, nous avons généré des lignées exprimant une protéine fluorescente verte dirigée par le promoteur p21SEN et ainsi, nous avons pu observer et suivre son activation à travers un signal vert durant la sénescence induite par les différents traitements utilisés. De plus, de façon intéressante, nos résultats ont également permis de montrer que cette expression de p21SEN durant la TIS semble être partiellement indépendante du facteur de transcription p53. Ainsi, nous suggérons que le promoteur p21SEN pourrait servir de rapporteur, en partie indépendant de p53, de l'induction de la sénescence dans un modèle utilisant un système de surveillance non invasif des décisions relatives au devenir des cellules dans le cancer de l'ovaire. / Ovarian carcinoma is one of the deadliest gynecological tumors worldwide, and particularly in Canada. In fact, it is the third most common cancer of the female reproductive system in Canada, according to the Canadian Cancer Society, which estimates that out of 3,000 Canadian women diagnosed with ovarian cancer in 2022, around 1,950 will not survive the disease. First-line treatments for this cancer include cytoreductive surgery combined with platinum and taxane chemotherapy such as the combination of the anticancer drugs Carboplatin and Paclitaxel. Other treatments include radiation therapy and, more recently, poly (ADP-ribose) polymerase inhibitors (PARPi) such as Olaparib, which are now used as first-line therapy for this type of cancer. These treatments can lead to different cell fate decisions, involving not only cancer cell death or survival, but also a treatment-induced proliferation arrest called TIS for therapy-induced senescence. While cell fate decisions are critical to the outcome of cancer treatment, our ability to measure cell fate in real time in cancer is extremely limited. For this reason, there are no ovarian cancer models that can provide non-invasive monitoring of cell fate at specific time points with tailored biomarkers, to decipher the role of different cell fates, or to serve as accurate experimental controls in preclinical testing of fate-based intervention strategies. Nevertheless, we have demonstrated that a fragment of the p21 promoter, which we have termed p21SEN, is expressed only during radiation-, chemotherapy-, and PARPi-induced senescence in clear cell ovarian adenocarcinoma cell lines (TOV21G). Indeed, we generated cell lines expressing a green fluorescent protein directed by the p21SEN promoter and thus, we were able to observe and follow its activation through a green signal during the senescence induced by the different treatments used. Moreover, interestingly, our results also showed that this expression of p21SEN during TIS seems to be partially independent of the transcription factor p53. Thus, we suggest that the p21SEN promoter could serve as a partially p53-independent reporter of senescence induction in a model using a non-invasive monitoring system of cell fate decisions in ovarian cancer.

O melanoma cutâneo é a neoplasia de pele de maior mortalidade. A imprevisibilidade de sua evolução é uma de suas características principais, o tratamento do tumor primário é, atualmente, de pouca morbidade e, na doença disseminada, as opções terapêuticas são pouco eficazes. É fundamental a pesquisa de marcadores tumorais que permitam a previsão da evolução, melhor compreensão da patogênese do melanoma e possibilitem a descoberta de alvos moleculares. Nesse contexto, estudos genéticos mostraram a importância da regulação do ciclo celular, especialmente a passagem da fase G1-S. Importantes fatores envolvidos compõem a cascata da proteína Rb (p16, ciclina D1, CDK4 e pRb) e da proteína p53 (p53 e p21). Objetivo: verificar a frequência da expressão de p16, ciclina D1,CDK4, pRb, p53 e p21 em melanomas cutâneos de cabeça, pescoço e tronco e sua relação com prognóstico. Métodos: Estudo retrospectivo envolvendo 46 pacientes (sendo 67,3% homens, idade média 57,7 ± 15,8 anos) com melanoma cutâneo de cabeça, pescoço e tronco que foram tratados pela mesma equipe com seguimento mínimo de dois anos. Foram estudados fatores clínicos (topografia do tumor primário, tempo de seguimento, ocorrência de metástases e óbito relacionado), histopatológicos (tipo histológico, índice de Clark, índice de Breslow) e análise imuno-histoquímica pela técnica de micro-array para as proteínas reguladoras do ciclo celular p16, ciclina D1, CDK4, pRb, p53 e p21. Resultados: Houve proporção igualitária entre as topografias (23 casos em tronco, 23 em cabeça e pescoço). Treze pacientes com Clark I (29,5%), cinco com II (11,3%), 16 com III (36,5%), 10 com IV (22,7%) e nenhum com Clark V. A média das medidas de Breslow foi 0,96 (DP=1,01). O seguimento médio foi de 77 meses (DP=47). Oito dos 46 pacientes (17,3%) tiveram evolução desfavorável, com seis óbitos relacionados. A idade foi mais elevada no grupo com evolução desfavorável (p=0,04). Houve expressão de p16 em 80%, ciclina D1 em 58,9%, CDK4 em 43,5%, pRb em 58,5%, p53 em 53,6% e p21 em 52,3% dos melanomas. Em análise univariada, a expressão do p21 foi relacionada com evolução desfavorável (p=0,04), o que não foi observado com a expressão dos outros marcadores (p>0,05). Conclusão: A expressão da proteína p21 nos melanomas cutâneos de cabeça, pescoço e tronco foi relacionada com evolução desfavorável, o que não ocorreu com outros fatores envolvidos na regulação do ciclo celular / Melanoma is the most lethal skin cancer. The outcome of melanoma is not predictable in most cases. Although the treatment for the primary tumor is well tolerated, there are no effective therapeutic options in disseminated disease. Efforts are being made in the search for tumoral markers that may predict outcome, increase the comprehension of melanoma pathogenesis, and may also help the search for molecular targets. In this issue, genetic studies concerning the regulation of cell cycle, including the G1-S checkpoint, are important. The retinoblastoma protein (pRb) pathway (p16, cyclin D1, CDK4 and pRb) and the p53 pathway (p53 and p21) are part of this regulation. Objectives: to verify the expression of p16, cyclin D1, CDK4, pRb, p53 and p21 in head, neck and trunk melanomas, and its correlation with prognosis. Method: Retrospective study approved by institution ethics committee. Fourtysix head, neck and trunk melanoma patients (67.3% men, mean age 57.7±15.8) treated by a single surgeon with minimum 2-years follow-up were enrolled. Clinical factors (primary tumor location, follow-up period, metastasis or related deaths), pathologic (histological subtype, Clark and Breslow index) and microarray immunohystochemical analysis of the cell cycle proteins p16, cyclin D1, CDK4, pRb, p53 and p21. Results: Location of the primary tumor was equal for head/neck and trunk (50% each). Thirteen patients were classified as Clark I (29.5%), five as Clark II (11.3%), 16 as Clark III (36.5%), 10 as IV (22.7%), none as Clark V. Mean Breslow measure was 0.96±1.01. Mean follow-up was 77±47 months. Eight patients (17.3%) had bad outcome, with six related deaths. Patients with worse outcome had a higher mean age at diagnosis (p=0,04). Expression of p16 was positive in 80%. Cyclin D1 was positive in 58.9%. CDK4 was positive in 43.5%. pRb was positive in 58.5%. p53 was positive in 53.6%. p21 was positive in 52.3%. Univariated analysis showed that p21 expression was related to worse outcome (p=0,04), while the other markers were not (p>0,05). Conclusion: p21 expression in head, neck and trunk melanomas was related to worse outcome. Expression of the other cell cycle regulators proteins was not