Intrinsic Resistance to Osimertinib in EGFR Mutated NSCLC Cell Lines Induced by Alteration in Cell-Cycle Regulators.

BACKGROUND: Cell-cycle regulators are mutated in approximately 40% of all cancer types and have already been linked to worse outcomes in non-small cell lung cancer adenocarcinomas treated with osimertinib. However, their exact role in osimertinib resistance has not been elucidated. OBJECTIVE: In this study, we aimed to evaluate how the CDK4/6-Rb axis may affect the sensitivity to osimertinib. METHODS: We genetically increased the level of CCND1 (Cyclin D1) and reduced the levels of CDKN2A (p16) in two different adenocarcinoma cell lines, PC9 and HCC827. We also retrospectively evaluated the outcome of patients with epidermal growth factor receptor-mutated advanced non-small cell lung cancer depending on their level of Cyclin D1 and p16. RESULTS: The modified clones showed higher proliferative capacity, modifications in cell-cycle phases, and higher migratory capacity than the parental cells. Cyclin D1-overexpressing clones were highly resistant to acute osimertinib treatment. CDKN2A knockdown conferred intrinsic resistance as well, although a longer time was required for adaption to the drug. In both cases, the resistant phenotype was epidermal growth factor receptor independent and associated with a higher level of Rb phosphorylation, which was unaffected by osimertinib treatment. Blocking the phosphorylation of Rb using abemaciclib, a CDK4/6 inhibitor, exerted an additive effect with osimertinib, increasing sensitivity to this drug and reverting the intrinsic resistant phenotype. In a group of 32 patients with epidermal growth factor receptor-mutated advanced non-small cell lung cancer, assessed for Cyclin D1 and p16 expression, we found that the p16-deleted group presented a lower overall response rate compared with the control group. CONCLUSIONS: We conclude that perturbation in cell-cycle regulators leads to intrinsic osimertinib resistance and worse patient outcomes.

EZH2 activates Wnt/ß-catenin signaling in human uterine fibroids, which is inhibited by the natural compound methyl jasmonate.

OBJECTIVE: To investigate the link between EZH2 and Wnt/ß-catenin signaling and its role in uterine fibroids (UFs) pathogenesis and explore the potential effect of natural compound methyl jasmonate (MJ) against UFs. DESIGN: EZH2 overexpression or inhibition was achieved in human uterine leiomyoma (HuLM) cells using EZH2-expressing adenovirus or chemical EZH2 inhibitor (DZNep), respectively. The HuLM and normal uterine smooth muscle cells were treated with 0.1-3 mM of MJ, and several experiments were employed. SETTING: Laboratory study. PATIENTS(S): None. INTERVENTION(S): Methyl jasmonate. MAIN OUTCOME MEASURE(S): Protein expression of EZH2, ß-catenin, and proliferating cell nuclear antigen (PCNA) was measured by Western blot as well as gene expression alterations of Wnt ligands (Wnt5A, Wnt5b, and Wnt9A), WISP1, CTNNB1, and its responsive gene PITX2 using quantitative real-time polymerase chain reaction. The protein and ribonucleic acid (RNA) levels of several markers were measured in MJ-treated or untreated HuLM cells, including EZH2 and ß-catenin, extracellular matrix markers collagen type 1 (COL1A1) and fibronectin (FN), proliferation markers cyclin D1 (CCND1) and PCNA, tumor suppressor marker p21, and apoptotic markers (BAX, cytochrome c, and cleaved caspase 3). RESULT(S): EZH2 overexpression significantly increased the gene expression of several Wnt ligands (PITX2, WISP1, WNT5A, WNT5B, and WNT9A), which increased nuclear translocation of ß-catenin and PCNA and eventually HuLM cell proliferation. EZH2 inhibition blocked Wnt/ß-catenin signaling activation where the aforementioned genes significantly decreased as well as PCNA, cyclin D1, and PITX2 protein expression compared with those in untreated HuLM. Methyl jasmonate showed a potent antiproliferative effect on HuLM cells in a dose- and time-dependent manner. Interestingly, the dose range (0.1-0.5 mM) showed a selective growth inhibitory effect on HuLM cells, not on normal uterine smooth muscle cells. Methyl jasmonate treatment at 0.5 mM for 24 hours significantly decreased both protein and RNA levels of EZH2, ß-catenin, COL1A1, FN, CCND1, PCNA, WISP1, and PITX2 but increased the protein levels of p21, BAX, cytochrome, c and cleaved caspase 3 compared with untreated HuLM. Methyl jasmonate-treated cells exhibited down-regulation in the RNA expression of 36 genes, including CTNNB1, CCND1, Wnt5A, Wnt5B, and Wnt9A, and up-regulation in the expression of 34 genes, including Wnt antagonist genes WIF1, PRICKlE1, and DKK1 compared with control, confirming the quantitative real-time polymerase chain reaction results. CONCLUSION(S): Our studies provide a novel link between EZH2 and the Wnt/ß-catenin signaling pathway in UFs. Targeting EZH2 with MJ interferes with the activation of wnt/ß-catenin signaling in our model. Methyl jasmonate may offer a promising therapeutic option as a nonhormonal and cost-effective treatment against UFs with favorable clinical utility, pending proven safe and efficient in human clinical trials.

Overexpressed Cyclin D1 and CDK4 proteins are responsible for the resistance to CDK4/6 inhibitor in breast cancer that can be reversed by PI3K/mTOR inhibitors.

CDK4/6 inhibitors are the standard treatment in advanced HR+/HER2- breast cancer patients. Nevertheless, the resistance to CDK4/6 inhibitors is inevitable and the strategies to overcome resistance are of great interest. Here, we show that the palbociclib-resistant breast cancer cells expressed significantly higher levels of Cyclin D1 and CDK4 proteins because of upregulated protein synthesis. Silencing Cyclin D1 or CDK4 led to cell cycle arrest while silencing Cyclin E1 or CDK2 restored the sensitivity to palbociclib. Furthermore, PI3K/mTOR pathway was hyper-activated in palbociclib-resistant cells, leading to more phosphorylated 4E-BP1 and higher levels of Cyclin D1 and CDK4 translation. Targeting PI3K/mTOR pathway with a specific PI3Kα inhibitor (BYL719) or an mTOR inhibitor (everolimus) reduced the protein levels of Cyclin D1 and CDK4, and restored the sensitivity to palbociclib. The tumor samples expressed significantly higher levels of Cyclin D1, CDK4, p-AKT and p-4E-BP1 after progression on palbociclib treatment. In conclusion, our findings suggest that overexpressed Cyclin D1 and CDK4 proteins lead to the resistance to CDK4/6 inhibitor and PI3K/mTOR inhibitors are able to restore the sensitivity to CDK4/6 inhibitors, which provides the biomarker and rationale for the combinational use of CDK4/6 inhibitors and PI3K/mTOR inhibitors after CDK4/6 inhibitor resistance in breast cancer.

Establishment and Characterization of Carboplatin-Resistant Retinoblastoma Cell Lines.

Carboplatin-based chemotherapy is the primary treatment option for the management of retinoblastoma, an intraocular malignant tumor observed in children. The aim of the present study was to establish carboplatin-resistant retinoblastoma cell lines to facilitate future research into the treatment of chemoresistant retinoblastoma. In total, two retinoblastoma cell lines, Y79 and SNUOT-Rb1, were treated with increasing concentrations of carboplatin to develop the carboplatin-resistant retinoblastoma cell lines (termed Y79/CBP and SNUOT-Rb1/CBP, respectively). To verify resistance to carboplatin, the degree of DNA fragmentation and the expression level of cleaved caspase-3 were evaluated in the cells, following carboplatin treatment. In addition, the newly developed carboplatin-resistant retinoblastoma cells formed in vivo intraocular tumors more effectively than their parental cells, even after the intravitreal injection of carboplatin. Interestingly, the proportion of cells in the G0/G1 phase was higher in Y79/CBP and SNUOT-Rb1/CBP cells than in their respective parental cells. In line with these data, the expression levels of cyclin D1 and cyclin D3 were decreased, whereas p18 and p27 expression was increased in the carboplatin-resistant cells. In addition, the expression levels of genes associated with multidrug resistance were increased. Thus, these carboplatin-resistant cell lines may serve as a useful tool in the study of chemoresistance in retinoblastoma and for the development potential therapeutics.

Patients with Invasive Lobular Carcinoma Show a Significant Increase in IRS-4 Expression Compared to Infiltrative Ductal Carcinoma-A Histopathological Study.

Background and Objectives: Breast cancer (BC) is the first diagnosed type of cancer and the second leading cause of cancer-related mortality in women. In addition, despite the improvement in treatment and survival in these patients, the global prevalence and incidence of this cancer are rising, and its mortality may be different according to the histological subtype. Invasive lobular carcinoma (ILC) is less common but entails a poorer prognosis than infiltrative ductal carcinoma (IDC), exhibiting a different clinical and histopathological profile. Deepening study on the molecular profile of both types of cancer may be of great aid to understand the carcinogenesis and progression of BC. In this sense, the aim of the present study was to explore the histological expression of Insulin receptor substrate 4 (IRS-4), cyclooxygenase 2 (COX-2), Cyclin D1 and retinoblastoma protein 1 (Rb1) in patients with ILC and IDC. Patients and Methods: Thus, breast tissue samples from 45 patients with ILC and from 45 subjects with IDC were analyzed in our study. Results: Interestingly, we observed that IRS-4, COX-2, Rb1 and Cyclin D1 were overexpressed in patients with ILC in comparison to IDC. Conclusions: These results may indicate a differential molecular profile between both types of tumors, which may explain the clinical differences among ILC and IDC. Further studies are warranted in order to shed light onto the molecular and translational implications of these components, also aiding to develop a possible targeted therapy to improve the clinical management of these patients.

Implication of ERBB2 as a Predictive Tool for Survival in Patients with Pancreatic Cancer in Histological Studies.

Pancreatic cancer will be positioned by the year 2030 as the second cause of oncological death after lung cancer. The pathophysiology of the most common variety, which involves the adenocarcinoma of the pancreas, represents one of the main challenges for current oncology to explain its tumorigenesis and create a targeted treatment. The tumor microenvironment, metastatic capacity, and lack of early diagnosis lead patients to present advanced stages at the time of diagnosis. Despite numerous efforts, little progress has been made in clinical outcomes and with respect to the improved survival of these patients. For this reason, in recent years, numerous diagnostic tests, treatments, and possible approaches in the fields of radiotherapy, chemotherapy, immunotherapy, and surgery have been developed to find a combination of methods that improves life expectancy in patients diagnosed with this disease. On the other hand, the scientific community has made numerous advances in the molecular bases of pancreatic cancer since several oncogenetic pathways have been described and the markers expressed by the tumor have proven to be useful in the prognosis of pancreatic adenocarcinoma. These molecular alterations allow the study of possible therapeutic targets that improve the prognosis of these patients, but even numerous tumor cell-individual interactions must be explained to understand the underlying pathophysiology causing the high mortality. Therefore, the purpose of our study is to examine the expression of markers such as EGFR, Cyclin D1, andCDK4 in order to find a relationship with the possible long-term prognostic factors of patients affected by pancreatic ductal adenocarcinoma. Our results show that there is a prognostic role for ErbB2, EGFR, beta catenin, cyclin D1, and CDK4. Of these, we highlight the clinical importance of ErbB2 in the survival rates of patients who overexpress this component.

Anticancer Effects of Tacrolimus on Induced Hepatocellular Carcinoma in Mice.

BACKGROUND: Tacrolimus is a calcineurin inhibitor widely used for immunological disorders. However, there is significant controversy regarding its effect on the liver. The present study was conducted to evaluate the anticancer effects of tacrolimus on an induced murine hepatocellular carcinoma (HCC) model and its possible hepatotoxicity at standard therapeutic doses. METHODS: Fifty-four male mice were divided into five groups: a control healthy group, control HCC group, tacrolimus-treated group, doxorubicin (DOXO)-treated group, and combined tacrolimus- and DOXO-treated group. The activity of liver enzymes, including alkaline phosphatase, gamma- glutamyl transferase, lactate dehydrogenase, alanine transaminase, and aspartate transaminase, was determined. Serum vascular endothelial growth factor (VEGF) was measured using an enzyme- linked immunosorbent assay. A quantitative real time- polymerase chain reaction (qRTPCR) was conducted to measure the expression of proliferating cell nuclear antigen (PCNA), Bax, and p53 mRNA. Immunohistochemical staining for cyclin D1 and VEGF was performed. RESULTS: Mice that received combined treatment with tacrolimus and DOXO exhibited the best improvement in all parameters when compared with the groups that received DOXO or tacrolimus alone (p < 0.001). CONCLUSION: The combination of DOXO and tacrolimus was more effective in the management of HCC compared with either agent alone. This improvement was detected by the reduction of liver enzymes and the improvement of the histopathological profile. The involved mechanisms included significant apoptosis induction demonstrated by upregulation of bax along with a reduction in angiogenesis demonstrated by downregulation of VEGF. This was accompanied by inhibition of cell cycle progression mediated by upregulated p53 and downregulated PCNA and cyclin D1.

Análise imuno-histoquímica da Bcl-2, Bcl-6, c-Myc e ciclina D1 em linfomas de células B da região oral / Immunohistochemical analysis of Bcl-2, Bcl-6, c-Myc and Cyclin D in B cell lymphomas of the oral region

Neste trabalho foram analisados 30 casos de linfomas de células B da região oral, fixados em solução de formaldeído e incluídos em parafina, através da técnica de imuno-histoquímica para as proteínas c-Myc, Bcl-2, Bcl-6 e ciclina D1. Dos casos analisados 40% foram positivos para a marcação para c-Myc, 33,3% para a marcação para ciclina D1, 83,3% para a marcação para Bcl-2 e 53,3% para a marcação para Bcl-6. Todos os casos foram diagnosticados como linfomas difusos de grandes células B, o subtipo de linfoma com a maior casuística. A análise destas proteínas é de fundamental importância para o diagnóstico e direcionamento do tratamento de doenças hematopoiéticas, pois estão envolvidas em vários processos de controle da transcrição gênica, do ciclo celular e dos processos apoptóticos e o aumento do conhecimento sobre sua ação em diferentes subtipos de linfomas pode corroborar outros estudos

In this study, 30 cases of formalin-fixed and paraffin-embedded B-cell lymphomas of the oral region were submitted to immunohistochemistry for the detection of proteins c-Myc, Bcl-2, Bcl-6 and cyclin D1. Fourty percent (40%) of the studied cases were positive for c-Myc, 10% for cyclin D1, 83.3% for Bcl-2 and 53.3% for Bcl-6. The analysis of these proteins has fundamental importance for the diagnosis and treatment course of hematopoietic diseases, because they are involved in various processes controlling gene transcription and cell cycle. All cases were diffuse large B-cell lymphomas, the subtype with the highest incidence. The analysis of these proteins is very important for the diagnosis and treatment course of hematopoietic diseases, because they are involved in various processes controlling gene transcription, cell cycle and apoptotic processes and an increase in the knowledge of their action in different subtypes of lymphomas can corroborate to other studies

Ação do Viscum album em cultivo celular de carcinoma epidermoide de cabeça e pescoço / Viscum album effect in head and neck squamous cell carcinoma cell culture

O carcinoma epidermoide de cabeça e pescoço, hoje considerada mundialmente uma das neoplasias mais frequentes desta região, tornou-se um problema de saúde pública, necessitando urgente de medidas a serem tomadas, a fim de melhorar a qualidade de vida dos pacientes acometidos, consequentemente aumentando a sobrevida, avaliada em cinco anos. O carcinoma epidermoide de cabeça e pescoço é uma doença complexa, e inclui vários fatores etiológicos, além de alterações moleculares, capazes de desencadear e dar continuidade a alguns eventos. No geral os carcinomas orais são tratados primeiramente com cirurgia excisional ou radioterapia individualmente, ou em combinação para os estágios mais avançados. As preparações dos extratos fermentados de Viscum album (VA), uma planta semiparasita da família das Lorantáceas, vêm sendo utilizada, principalmente em países da Europa, com resultados promissores no âmbito das terapias coadjuvantes, especialmente a medicina antroposófica. Em conjunto com as terapias convencionais, tem demonstrado uma melhora na qualidade de vida dos pacientes portadores de neoplasias malígnas. Estudos in vitro, realizados em células cancerígenas, têm demonstrado que vários tipos de VA podem apresentar citotoxicidade em células de carcinoma, sendo capazes de ativar a cascata apoptótica ou levando as células à necrose. Este estudo teve por objetivo verificar a ação de três tipos de extratos de VA (Iscador Qu Spezial, Iscador P e Iscador M), em linhagens celulares de carcinoma epidermoide de língua (SCC9 e SCC25). Para isso foi verificada a ação citotóxica do fármaco Iscador Qu Spezial, por meio do teste de viabilidade celular, para a obtenção da IC50...

Head and neck squamous cell carcinoma, one of the most common malignancies worldwide in this area, became a public health problem that requires urgent attitudes to be taken in order to improve the quality of life of the affected patients, increasing survival that today valued at five years. Head and neck squamous cell carcinoma is a complex disease which includes several etiologic factors and different molecular changes that may trigger and get on with some events. In general, oral carcinomas are treated primarily with surgical excision or radiotherapy alone or in combination for cases in more advanced stages. Preparations of fermented extracts from fermented Viscum album (VA), a plant from the Loranthaceae family have been used, mainly in European countries, with promising results as adjuvant therapies, especially in the Anthroposophy Medicine. In combination with conventional therapies, VA has lead to improvement in quality of life of patients with cancer. in vitro studies have demonstrated that various types of VA may have cytotoxicity in carcinoma cells being able to activate the apoptotic cascade or leading cells to necrosis. The present study aimed to verify the effect of three types of VA extracts (Iscador Qu Spezial, Iscador P and Iscador M) in squamous cell carcinoma of the tongue (SCC9 and SCC25). The cytotoxic action of Iscador Qu Spezial was verified by cell viability test obtaining the IC50. The three drugs were tested as follow: Tunnel to evaluate apoptosis, Annexin V and FITC/propidium iodide were evaluated by flow cytometry to quantify the apoptosis rate induced by the drugs...

Correlação entre COX-2 e ciclina D-1 após administração de tamoxifeno neoadjuvante em curto prazo no tratamento de carcinoma de mama / Correlation of COX-2 and ciclyn D-1 after short-time neoadjuvant tamoxifen on breast cancer

Introdução: O tamoxifeno é a droga utilizada há mais tempo na terapia hormonal do câncer de mama. A superexpressão da ciclina D-1 interfere negativamente no tratamento com tamoxifeno e pode contribuir para predição da falha terapêutica observada em algumas pacientes. COX-2 induz a oxidação de estrogênio a dietilestilbestrol e importante ação genotóxica na mama. Ciclina D-1 e COX-2 ainda não foram descritos associados em relação ao tratamento com tamoxifeno em curto período (14 dias). Objetivo: Avaliar os efeitos da administração neoadjuvante de tamoxifeno em curto prazo (14 dias) sobre a expressão de COX-2 e ciclina D -1 no tratamento do câncer de mama. Métodos: Estudo prospectivo randomizado realizado na disciplina de Mastologia da Unifesp. Vinte e cinco pacientes com carcinoma de mama nos estádios II e III, subdivididas em grupos (controle, n=13, e tratamento, n=12). As amostras de ciclina D-1 e COX-2 foram avaliadas antes e após o tratamento. A avaliação imuno-histoquímica foi realizada por meio de anticorpos policlonais para COX-2 (Novo castra - Clone 4H12) e ciclina D-1 (Novocastra - Clone DCS-6). Os resultados foram classificados de acordo com a fração e intensidade de coloração das células marcadas. Resultados: Observou-se positividade da COX-2 em 56% dos tumores, sem diferença significativa nos dois momentos da amostra (p = 0,39 - Mann Whitney test*1). A expressão da COX-2 não apresentou diferença significativa nas amostras pré e pós nos grupos controle e tratamento. Na amostra total do estudo, observou-se alteração da expressão da ciclina D-1 entre os dois momentos da amostra (teste de McNemar - Diferença = 36.00% (p = 0,06). Entre os grupos controle e tratamento, observou-se que a diferença das medianas de ciclina D-1 entre as amostras pós e pré (pós - pré) demonstrou tendência à significância estatística pelo teste de Mann-Whitney (p = 0,08). Conclusão: O tratamento neoadjuvante com tamoxifeno em curto prazo (14 dias) não foi capaz de modificar...

Introduction: Tamoxifen is the most used drug in the hormonal therapy of the breast cancer. Ciclyn D-J, one CCNDJ gene product's (PRADJ), is essential for the normal lobule-alveolar mammary development and acts in the cellular cycle control. Ciclyn D-I superexpression act negatively in tamoxifen treatment, and may contribute to predict the failure observed in some patients. COX-2 activity induces oestrogen oxidation to dietilstilbestrol and promotes genotoxics effects on the breast. Ciclyn D-1 and COX-2 association had not been described yet to short time tamoxifen treatment. Objective: Evaluate short time (14 days) neoadjuvant tamoxifen effects on COX-2 and ciclyn D-1 expression in breast cancer patients. Methods: Randomized prospective study in the Federal University of Sao Paulo. Twenty five patients with stage II and III breast cancer were included. The groups were control (n = 13) and treatment (n = 12). Ciclyn D-1 and COX-2 samples were evaluated before and after treatment. Imunohistochemistry was performed on the tissue sections using a polyclonal antibody to COX-2 (Novocastra - Clone 4H12) and cyclin D-1 (Novocastra - Clone DCS-6). The results were classified according Already score, based on the intensity and fraction marked cells. Results: COX-2 was positive in 56% of tumors. No significant difference was observed between the two groups (p = 0.39 Mann Whitney test). The Difference of cyclin D-1 medium (post - pre) in the control group was 5, while in the tamoxifen group was 0.5. (p=0.08, Mann Whitney test). Correlation between COX-2 and ciclyn D-1 was expressed by Pearson index (r). In treatment group moderate linear and positive correlation was observed (r = 0.51 - Pearson's index) (p = 0.08). It wasn't observed in control group (r = 0.42) (p = 0.12). Conclusion: Tamoxifen treatment in short time period (14 days) wasn't modified significantly COX-2 and ciclyn D-1 expression.

Failure of vaccination with idiotypic protein or DNA, (+/-IL-2), the depletion of regulatory T cells, or the blockade of CTLA-4 to prolong dormancy in mice with BCL1 lymphoma.

Immunization of mice with the idiotype (Id) immunoglobulin from the murine B cell lymphoma, BCL1, before inoculating tumor cells can induce tumor dormancy. In this model, the tumor cells grow for a short period of time and then regress. The mice live for months or years with approximately 1 million tumor cells in their spleens. Some mice relapse due to decreases in the anti-Id antibody titers or the development of mutations in the residual tumor cells which render them refractory to negative signaling by the anti-Id antibody. In this study we determined whether we could eliminate the residual dormant cells by using a DNA vaccine against the Id or by immunomodulation of T-cell subsets in vivo. Our results demonstrate that dormancy can be maintained by further immunizations with either the BCL1 Id protein or DNA vaccine encoding its single-chain Fv fragment. We also found that a cytotoxic T-cell response was not induced by either in vivo administration of vaccine alone or by the vaccine plus interleukin-2. In addition the injection of anti-cytotoxic T-lymphocyte-associate antigen did not prolong dormancy. Finally, the in vivo administration of anti-CD25 to deplete regulatory T cells did not prolong dormancy. Dormancy in this model is dependent primarily upon anti-Id antibodies, our results suggest that other strategies to target residual dormant BCL1 cells are warranted. They also suggest that the elimination of dormant tumor may represent a greater challenge than the elimination of primary tumors.