Treatment of palbociclib in hormone receptor positive breast cancer: a real-world study and efficacy prediction model / 中华肿瘤杂志

Objective: To summarize the clinical use of palbociclib and evaluate its efficacy and safety in hormone-receptor (HR)-positive advanced breast cancer patients. Methods: We retrospectively analyzed data from 66 HR-positive metastatic breast cancer patients treated with palbociclib and endocrine therapy at the Department of Oncology in the First Affiliated Hospital with Nanjing Medical University between 2018 and 2020. We evaluated the factors affecting the efficacy of palbociclib using Kaplan-Meier method and Log-rank test for survival analysis and Cox regressions for multivariate analysis. Nomogram model was built for predicting prognosis among HR-positive breast cancer patients who received palbociclib. Concordance index (C-index) and calibration curve were used for internal validation to assess the predictive ability and conformity of the model. Results: Of the 66 patients treated with palbociclib, 33.3%(22), 42.4%(28) and 24.2%(16) patients were treated without endocrine therapy, first-line endocrine therapy, second-line or above endocrine therapy after recurrence, respectively. 36.4%(24) patients had hepatic metastasis, 16.7% (11) patients were sensitive to previous endocrine therapy, 27.3%(18/66) patients had primary resistance to endocrine therapy, while 56.1% (37) patients had secondary resistance to endocrine therapy. The overall response rate was 14.3% (95% CI: 6.7%, 25.4%) and clinical benefit rate was 58.7% (95% CI: 45.6%, 71.0%). Better clinical outcomes were associated with non-hepatic metastasis (P=0.001), sensitive/secondary resistant to previous endocrine therapy (P=0.004), no or only one line of chemotherapy for metastatic breast cancer (P=0.004), recent pathological confirmation of immunohistochemical analysis (P=0.025). Hepatic metastasis (P=0.005) and primary resistance to endocrine therapy (P=0.016) were the independent risk factors of progression free survival. The C-index of predictive probability for the nomogram constructed from the patient clinical characteristics (whether liver metastasis, whether primary endocrine resistance, lines of chemotherapy after metastasis, lines of endocrine therapy, number of metastatic sites, and time to last immunohistochemistry) to predict the progression-free survival at 6 and 12 months for patients was 69.7% and 72.1%, respectively. The most common adverse events were hematologic toxicities. Conclusions: Our report indicates that palbociclib combined with endocrine therapy for HR-positive recurrent metastatic breast cancer is effective and safe; patients with hepatic metastases and primary resistance to endocrine therapy have worse prognoses and are independent risk factors for progression after palbociclib therapy. The constructed nomogram could help predict the survival and guide the use of palbociclib.

RRM2 promotes tumor progression by interfering with G2/M cycle of prostate cancer cells / 现代泌尿外科杂志

【Objective】 To investigate the role of RRM2 in prostate cancer and the mechanism. 【Methods】 The data of prostate cancer expression profile were downloaded from The Cancer Genome Atlas (TCGA). The correlation between RRM2 expression and clinicopathological features and prognosis of prostate cancer was analyzed. The protein expressions of RRM2 in 55 cases of prostate cancer and 38 benign tissues were determined with immunohistochemistry (IHC). The effects of RRM2 on the biological process of prostate cancer were assessed with bioinformatic analysis. The biological process of RRM2 affecting the progression of prostate cancer was verified with Western blot and flow cytometry. 【Results】 RRM2 was highly expressed in prostate cancer, and the expression was positively correlated with the clinical stage, pathological grade and metastasis of prostate cancer (P<0.05). Higher RRM2 expression predicted poorer survival. RRM2 co-expression positively correlated genes were involved in cell cycle pathways, pyrimidine nucleotide metabolism, and biological processes such as RNA transport. Cell cycle pathways were significantly enriched. RRM2 was highly correlated with CDK1 and PCNA molecules. RRM2 knockdown reduced the protein expressions of CDK1 and PCNA in DU145 and LNCap cell lines, which were arrested in the G2/M phase. 【Conclusion】 RRM2 promotes tumor progression by interfering with G2/M cycle of prostate cancer cells.

LncRNA SBF2-AS1 Regulates Invasion and Proliferation of Hepatocellular Carcinoma Cells Through miR-372-3p/CDK6 Axis / 肿瘤防治研究

Objective To investigate the effects of lncRNA SBF2-AS1 on the proliferation and invasion of hepatoma cells by regulating the miR-372-3p/CDK6 pathway. Methods Bel7402 and SK-hep1 cells were selected as research objects. The expression levels of SBF2-AS1, miR-372-3p, and CDK6 were up- or down-regulated according to different experimental stages, while the expression levels of miR-372-3p and CDK6 in cells were detected by real-time fluorescence quantitative PCR and Western blot. Dual luciferase reporter assay verified the targeting relationships between SBF2-AS1 and miR-372-3p as well as miR-372-3p and CDK6, respectively. CCK-8, colony formation assay, Transwell, cell cycle assay, and flow cytometry were used to analyze cell proliferation, colony formation, migration/invasion ability, cell cycle activity, and apoptosis. Results SBF2-AS1 was highly expressed in hepatocellular carcinoma cells (P<0.05). SBF2-AS1 knockdown resulted in decreased proliferation and invasion of Bel7402 and SK-hep1 cells (P<0.05). After miR-372-3p knockdown, the proliferation capacity and invasion number of Bel7402 cells were significantly increased. However, the above results were reversed after SBF2-AS1 knockdown (P<0.05). In addition, miR-372-3p targeted CDK6 and inhibited its expression, although over-expressing SFB2-AS1 could reverse the above results (P<0.05). Over-expressing CDK6 could reverse the inhibition of over-expressing miR-372-3p on the proliferation and invasion of Bel7402 cells. Conclusion LncRNA SBF2-AS1 can positively regulate the expression of CDK6 through miR-372-3p. It can also influence the distribution of cell cycle and affect the proliferation and invasion abilities of hepatocellular carcinoma cells.

Study on the modification and anti-tumor activity of silybin derivatives for CDK4/6 targeted / 药学学报

By using computer-aided drug design, the activities group model which CDK4/6 inhibitors on the market were introduced to silybin C-7, and a series of silybin derivatives were designed and synthesized, and the structure was confirmed by MS, 13C NMR and 1H NMR. The in vitro antitumor activity evaluation of the target compound was carried out by MTT method, and the in vitro anti-tumor activity was carried out in human hepatocellular carcinoma cells (HepG-2). Experimental results show that all compounds are higher than the activity of the parent silybin, of which compound I1 has a certain inhibitory effect on human HepG-2 cells, which is worth further study.

Consensus on the clinical use of CDK4/6 inhibitors for the treatment of hormone receptor-positive human epidermal growth factor receptor 2-negative breast cancer (2023 edition) / 中华肿瘤杂志

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have led transformative breakthrough of clinical therapy for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER-2)-negative breast cancer patients. CDK4/6 inhibitors that have been marketed in China include Ribociclib, Palbociclib, Abemaciclib and Dalpiciclib. For HR-positive HER-2-negative locally advanced and metastatic breast cancer, CDK4/6 inhibitors combined with endocrine therapy have become standard regimen, which can prolong the survival of patients. In the adjuvant treatment stage of early breast cancer, CDK4/6 inhibitors have also achieved positive results and been approved for indications. At present, CDK4/6 inhibitors have been widely used in clinical practice in China. In order to further improve the standardized application of CDK4/6 inhibitors in China, the Breast Cancer Expert Committee of the National Center for Cancer Quality Control and the Professional Committee of Clinical Research of Cancer Drugs of the Chinese Anti-Cancer Association organized the related expert to update the consensus based on the "CDK4/6 inhibitor consensus on clinical application of in the treatment of hormone receptor positive human epidermal growth factor receptor 2 negative advanced breast cancer (2021 edition)" . The updated consensus systematically introduces the pharmacological characteristics, drug monitoring and adverse event management, etc., of CDK4/6 inhibitors to promote the accuracy of clinical decision-making with the ultimate goal to prolong the overall survival of patients and improve the quality of life.

Guidelines for pharmaceutical care of endocrine therapeutics for breast cancer(2023 edition) / 中华肿瘤杂志

Endocrine therapy is one of the primary treatment methods for hormone receptor-positive breast cancer patients. As of June 1 2023, the National Medical Product Administration has approved 56 drugs related to endocrine therapy in patients with HR+ /HER-2- breast cancer (including generic drugs that have passed the consistency evaluation), including 44 endocrine drugs which can be categorized according to their mechanisms of action into selective estrogen receptor modulators, selective estrogen receptor down-regulators, aromatase inhibitors, luteinizing hormone-releasing hormone analogs, and progestogens and 12 targeted drugs for combined with endocrine therapy, including CDK4/6 inhibitors, mTOR inhibitors, and HDAC inhibitors. The different pharmacological characteristics, mechanisms of action, and long-term medication factors of breast cancer endocrine therapy-related drugs can directly affect patients' medication adherence and medication safety. To standardize the pharmaceutical care of endocrine therapy drugs for breast cancer and promote rational use in clinical settings, the Oncology Specialty Pharmacist Subcommittee, in conjunction with multidisciplinary experts nationwide, has developed the "Guidelines for pharmaceutical care of endocrine therapy drugs for breast cancer (2023 edition)". The guidelines is based on clinical evidence-based evidence, relevant regulations of pharmaceutical management, and pharmaceutical care practices. The Delphi method and expert interviews were used to formulate the guidelines. The GRADE approach was used for assessing the certainty of evidence. This guideline mainly focuses on endocrine therapy for HR+ /HER-2- breast cancer patients. Due to space constraints, HER-2 positive targeted drugs were not included in the guideline. It covers 6 dimensions and 22 key problems of pharmaceutical care in the whole process of drug therapy, providing a scientific basis for pharmacists to carry out pharmaceutical care of such drugs.

Effects of Sijunzi decoction-containing serum on polyamine/HuR signaling pathway during IEC-6 cell proliferation / 中国药理学通报

Aim To investigate the effect of Sijunzi Decoction on mRNA and protein expression related to growth and cell cycle in polyamine/HuR signaling pathway during small intestinal epithelial cell (IEC-6) proliferation, and to explore its mechanism on intestinal mucosal injury repair. Methods Sijunzi Decoction-containing serum (SJZD) was prepared from SD rats, the expression of HuR protein in cytoplasm and nucleus was analyzed by immunofluorescence and Western blot, the mRNA level of activating transcription factor-2 (A T F - 2), JunD and cyclin dependent kinase 4 (CDK4) were determined by real-time fluorescent quantitative PCR (RT-PCR), Western blot was used to detect protein level of HuR, ATF-2, JunD and CDK4, and flow cytometry was applied to analyse cell cycle distribution. Results Compared with the control group, the mRNA and protein expression of ATF-2 and JunD decreased, while the expression of Cdk4 mRNA and protein increased in SZJD group, and the proportion of G

Predicting and overcoming resistance to CDK9 inhibitors for cancer therapy

Abnormally activated CDK9 participates in the super-enhancer mediated transcription of short-lived proteins required for cancer cell survival. Targeting CDK9 has shown potent anti-tumor activity in clinical trials among different cancers. However, the study and knowledge on drug resistance to CDK9 inhibitors are very limited. In this study, we established an AML cell line with acquired resistance to a highly selective CDK9 inhibitor BAY1251152. Through genomic sequencing, we identified in the kinase domain of CDK9 a mutation L156F, which is also a coding SNP in the CDK9 gene. By knocking in L156F into cancer cells using CRISPR/Cas9, we found that single CDK9 L156F could drive the resistance to CDK9 inhibitors, not only ATP competitive inhibitor but also PROTAC degrader. Mechanistically, CDK9 L156F disrupts the binding with inhibitors due to steric hindrance, further, the mutation affects the thermal stability and catalytic activity of CDK9 protein. To overcome the drug resistance mediated by the CDK9-L156F mutation, we discovered a compound, IHMT-CDK9-36 which showed potent inhibition activity both for CDK9 WT and L156F mutant. Together, we report a novel resistance mechanism for CDK9 inhibitors and provide a novel chemical scaffold for the future development of CDK9 inhibitors.

Discovery of small molecule degraders for modulating cell cycle / 医学前沿

The cell cycle is a complex process that involves DNA replication, protein expression, and cell division. Dysregulation of the cell cycle is associated with various diseases. Cyclin-dependent kinases (CDKs) and their corresponding cyclins are major proteins that regulate the cell cycle. In contrast to inhibition, a new approach called proteolysis-targeting chimeras (PROTACs) and molecular glues can eliminate both enzymatic and scaffold functions of CDKs and cyclins, achieving targeted degradation. The field of PROTACs and molecular glues has developed rapidly in recent years. In this article, we aim to summarize the latest developments of CDKs and cyclin protein degraders. The selectivity, application, validation and the current state of each CDK degrader will be overviewed. Additionally, possible methods are discussed for the development of degraders for CDK members that still lack them. Overall, this article provides a comprehensive summary of the latest advancements in CDK and cyclin protein degraders, which will be helpful for researchers working on this topic.

Extracellular vesicle-carried GTF2I from mesenchymal stem cells promotes the expression of tumor-suppressive FAT1 and inhibits stemness maintenance in thyroid carcinoma / 医学前沿

Through bioinformatics predictions, we identified that GTF2I and FAT1 were downregulated in thyroid carcinoma (TC). Further, Pearson's correlation coefficient revealed a positive correlation between GTF2I expression and FAT1 expression. Therefore, we selected them for this present study, where the effects of bone marrow mesenchymal stem cell-derived EVs (BMSDs-EVs) enriched with GTF2I were evaluated on the epithelial-to-mesenchymal transition (EMT) and stemness maintenance in TC. The under-expression of GTF2I and FAT1 was validated in TC cell lines. Ectopically expressed GTF2I and FAT1 were found to augment malignant phenotypes of TC cells, EMT, and stemness maintenance. Mechanistic studies revealed that GTF2I bound to the promoter region of FAT1 and consequently upregulated its expression. MSC-EVs could shuttle GTF2I into TPC-1 cells, where GTF2I inhibited TC malignant phenotypes, EMT, and stemness maintenance by increasing the expression of FAT1 and facilitating the FAT1-mediated CDK4/FOXM1 downregulation. In vivo experiments confirmed that silencing of GTF2I accelerated tumor growth in nude mice. Taken together, our work suggests that GTF2I transferred by MSC-EVs confer antioncogenic effects through the FAT1/CDK4/FOXM1 axis and may be used as a promising biomarker for TC treatment.

Advances of the regulatory mechanism of cyclin, cyclin- dependent kinases and related kinase inhibitors in cell cycle progression / 生物工程学报

Cell cycle plays a crucial role in cell development. Cell cycle progression is mainly regulated by cyclin dependent kinase (CDK), cyclin and endogenous CDK inhibitor (CKI). Among these, CDK is the main cell cycle regulator, binding to cyclin to form the cyclin-CDK complex, which phosphorylates hundreds of substrates and regulates interphase and mitotic progression. Abnormal activity of various cell cycle proteins can cause uncontrolled proliferation of cancer cells, which leads to cancer development. Therefore, understanding the changes in CDK activity, cyclin-CDK assembly and the role of CDK inhibitors will help to understand the underlying regulatory processes in cell cycle progression, as well as provide a basis for the treatment of cancer and disease and the development of CDK inhibitor-based therapeutic agents. This review focuses on the key events of CDK activation or inactivation, and summarizes the regulatory processes of cyclin-CDK at specific times and locations, as well as the progress of research on relevant CDK inhibitor therapeutics in cancer and disease. The review concludes with a brief description of the current challenges of the cell cycle process, with the aim to provide scientific references and new ideas for further research on cell cycle process.

Complete response in metastatic breast cancer with visceral crisis using a combination of cyclin-dependent kinase 4/6 inhibitor and aromatase inhibitor: A case report from the eastern region of India

Patients with metastatic breast cancer (MBC) in visceral crisis require systemic chemotherapy. However, a coexisting cardiac failure that contradicts the use of systemic chemotherapy often demands an alternative treatment. Here, we report a case of hormone-receptor-positive MBC with cardiological comorbidities. She was treated with a combination treatment of tablet Ribociclib (600 mg once daily for 21 days followed by 7 days gap) and tablet Letrozole (2.5 mg once daily). The patient had a complete metabolic response in 18-Fluorodeoxyglucose Positron Emission tomography-Computed Tomography (18F-FDG PET/CT), after 6 months of treatment. Combination treatment with Ribociclib and Letrozole is beneficial in postmenopausal females with hormone receptor-positive and human epidermal growth factor receptor 2 neu-negative MBC in visceral crisis who have a contraindication to chemotherapy.

Icariin Inhibits Proliferation of CLC5 Hepatoma Cells via Akt/GSK3β/CDK Pathway / 中国实验方剂学杂志

ObjectiveTo study the effect of icariin on the proliferative capacity of hepatocellular carcinoma cell line CLC5 and the underlying mechanism. MethodThe targets of icariin were screened out by network pharmacology， and the target network and protein-protein interaction （PPI） network were constructed to predict the possible targets and pathways of icariin. CCK-8 assay was employed to explore the effects of different concentrations （0， 6.25， 12.5， 25， 50 μmol·L-1） of icariin on the viability of CLC5 cells. Further， CLC5 cells were treated with 0， 25， 50 μmol·L-1 icariin， and the effect of icariin on CLC5 cell proliferation was examined by Edu-488 assay and clone formation assay （CFA）. Western blot was employed to measure the expression levels of proteins in the protein kinase B （Akt）/glycogen synthase kinase 3β （GSK3β）/cell cycle-dependent kinase （CDK） pathway in the CLC5 cells exposed to different concentrations of icariin. ResultNetwork pharmacological analysis revealed that icariin may inhibit the hepatocellular carcinoma via cell cycle arrest and inhibition of tumor cell proliferation. Compared with the blank group， icariin decreased the viability of CLC5 cells in a time- and concentration-dependent manner （P<0.01） and reduced the positive rate of Edu-488 and the colonies in CFA （P<0.05， P<0.01）. Moreover， icariin down-regulated the protein levels of p-Akt， p-GSK3β， CDK4， and CyclinD1 （P<0.05， P<0.01）. ConclusionIcariin may block cell cycle to suppress the proliferation of CLC5 cells via inhibiting the Akt/GSK3β/CDK pathway.

lncRNA CDK5RAP3 regulates the proliferation and invasion of gastric cancer cells via miR-223-3p / 国际外科学杂志

Objective:To explore the expression of long non-coding RNA (lncRNA) CDK5RAP3 in gastric cancer tissue and its regulatory effect on gastric cancer cell proliferation and invasion.Methods:The expression differences of CDK5RAP3 in gastric cancer tissues and adjacent tissues were analyzed by TCGA database. By transfecting the pcDNA3.1-CDK5RAP3 plasmid into Hs-746T cells, a gastric cancer cell line overexpressing CDK5RAP3 (CDK5RAP3 group) was constructed, and the pcDNA3.1 plasmid was transfected into Hs-746T cells as a control group. The changes of CDK5RAP3 expression in the two groups of cells were detected by real-time quantitative PCR (qRT-PCR). The effects of overexpression of CDK5RAP3 on the proliferation and invasion of Hs-746T cells were detected by CCK-8 assay and Transwell assay, respectively. The binding sites of CDK5RAP3 and miR-223-3p were predicted by the starBase v2.0 database. The direct binding of CDK5RAP3 and miR-223-3p was verified by dual-luciferase reporter gene experiment. The expression levels of miR-223-3p in Hs-746T cells in each group were detected by qRT-PCR. Western blot was used to detect the expression levels of proliferation proteins and invasion proteins in Hs-746T cells in each group. The experimental data were analyzed by SPSS 17.0 software, and the measurement data conforming to the normal distribution were expressed as Mean±SD. The t-test was used to compare between two groups, and the one-way analysis of variance was used to compare the means of multiple groups. Results:Compared with adjacent tissues, the expression level of CDK5RAP3 in gastric cancer tissues was significantly lower ( P<0.01). The expressions of CDK5RAP3 in Hs-746T cells in the control group and CDK5RAP3 group were (1.08±0.77) and (10.63±2.14), respectively, and the difference was statistically significant ( P<0.01). Up-regulation of CDK5RAP3 significantly decreased the proliferation activity of Hs-746T cells ( P<0.05). The number of invasive cells in the control group and CDK5RAP3 group were (137.80±28.72) and (57.76±24.95), respectively, and the difference was statistically significant ( P<0.01). CDK5RAP3 could directly bind miR-223-3p ( P<0.01). The expression of miR-223-3p in Hs-746T cells in control group and CDK5RAP3 group were (6.22±1.20) and (1.01±0.98), respectively, and the difference was statistically significant ( P<0.01). Compared with the control group, up-regulation of CDK5RAP3 significantly reduced the expression levels of proliferation and invasive proteins. Conclusion:The expression of CDK5RAP3 is low in gastric cancer tissue, and CDK5RAP3 inhibits the proliferation and invasion of gastric cancer Hs-746T cells by targeting miR-223-3p.

Expert consensus on the management of adverse events of CDK4/6 inhibitors in breast cancer / 中华肿瘤杂志

Cyclin-dependent kinases 4/6 (CDK4/6) inhibitors are anti-tumor agents for the treatment of hormone receptor-positive breast cancer. Palbociclib, abemaciclib and dalpiciclib have been approved for the treatment of breast cancer in China. Common adverse effects of CDK4/6 inhibitors include bone marrow suppression, gastrointestinal toxicities, liver dysfunction, and skin or subcutaneous tissue adverse reactions (AEs). The Breast Cancer Expert Group of Chinese Society of Clinical Oncology (CSCO) summarized the incidence, clinical manifestations, and grading of the AEs. This expert consensus reports measures of AE management on the basis of experience of clinical practice and the latest advances worldwide, aiming to guide clinical practice by the way of managing AE and help to choose the best treatment regimen.

G6PD Regulates Cyclin E1 and CDK2 to Promote Cell Proliferation and Its Prognostic Value in Clear Cell Renal Cell Carcinoma / 中国生物化学与分子生物学报

Clear cell renal cell carcinoma (ccRCC) has been proved to be a metabolic disease with high

Optimizing the effective doses of mitomycin C, 5-fluorouracil, and their combination on cultivated basal cell carcinoma / Otimização da dose efetiva da mitomicina C, do 5fluorouracil e da combinação de ambos em culturas de células de carcinoma basocelular

ABSTRACT Purpose: This study aimed to optimize the effective doses of mitomycin C, 5-fluorouracil, and their combination on cultivated basal cell carcinoma. Methods: Cultivated basal cell carcinoma and fibroblastic cells were treated with different concentrations of mitomycin C, 5-fluorouracil, and their combination. Cell viability, cell cycle, apoptosis, and expression levels of TP53, CDKN1A, and CDK6 were investigated. The most effective drug with its optimum dosage was administered via multiple intralesional injections to a 65-year-old woman with advanced periorbital nodulo-ulcerative BCC. Results: The concentrations of 0.00312 and 0.312 mg/mL were considered optimum for mitomycin C and 5-fluorouracil, respectively. The mean viabilities of basal cell carcinoma treated with mitomycin C alone and its combination with 5-fluorouracil were significantly less than those of the controls (p=0.002 and p=0.04, respectively). The cell cycle of all the treated basal cell carcinoma groups was arrested in the S phase. The apoptotic rates (p=0.002) of mitomycin C treated basal cell carcinoma were higher than those of the other treated cells, and their TP53 was significantly upregulated (p=0.0001). Moreover, CDKN1A was upregulated, whereas CDK6 was downregulated in basal cell carcinoma treated with either 5-fluorouracil (p=0.0001 and p=0.01, respectively) or the combination of 5-fluorouracil and mitomycin C (p=0.007 and p=0.001, respectively). Basal cell carcinoma lesions were significantly alleviated following mitomycin C injections in the reported patient. Conclusion: Our in vitro results revealed that the effective doses of mitomycin C and 5-fluorouracil on cultivated basal cell carcinoma were optimized. Mitomycin C was more effective in inducing the apoptosis of basal cell carcinoma than 5-fluorouracil and their combination. The intralesional injections of the optimum dose of mitomycin C could be proposed for the nonsurgical treatment of advanced eyelid basal cell carcinoma.

RESUMO Objetivo: Otimizar a dose efetiva de mitomicina C, 5fluorouracil e da combinação de ambos em culturas de células de carcinoma basocelular (CBC). Métodos: Culturas de células de células de carcinoma basocelular e de fibroblastos foram tratadas com diferentes concentrações de mitomicina C, 5fluorouracil e combinação de ambos. Além disto, foram investigados a viabilidade celular, o ciclo celular, a apoptose e a expressão dos genes TP53, CDKN1A e CDK6. O medicamento mais eficaz, em sua dosagem otimizada, foi administrado em últiplas injeções intralesionais em uma mulher de 65 anos com carcinoma basocelular nódulo-ulcerativo periorbital avançado. Resultados: A concentração de 0,00312 mg/mL de mitomicina C e a de 0,312 mg/mL de 5fluorouracil foram consideradas as ideias. A viabilidade média das células de carcinoma basocelular tratadas com mitomicina C isoladamente e em combinação foi significativamente menor que nas células de controle (respectivamente, p=0,002 e p=0,04). Todos os grupos de carcinoma basocelular tratados demonstraram interrupção do ciclo celular na fase S. As células de carcinoma basocelular tratadas com mitomicina C mostraram maiores taxas de apoptose (p=0,002) e significativa regulação positiva do gene TP53 (p=0,0001). Além disso, o gene CDKN1A foi positivamente regulado e o gene CDK6 foi negativamente regulado em células de carcinoma basocelular tratadas com 5fluorouracil (respectivamente, p=0,0001 e p=0,01) ou com a combinação de medicamentos (respectivamente, p=0,007 e p=0,001). Injeções posteriores de mitomicina C na paciente em questão levaram à melhora significativa da lesão do carcinoma basocelular. Conclusão: Nossos resultados in vitro otimizaram as doses efetivas de mitomicina C e 5fluorouracil na cultura de células de carcinoma basocelular e mostraram que a mitomicina C tem mais eficácia na apoptose de células de carcinoma basocelular do que o 5fluorouracil e a combinação de ambos. Injeções intralesionais de doses otimizadas de mitomicina C podem ser propostas para o tratamento não cirúrgico do células de carcinoma basocelular avançado de pálpebra.

CRISPR/Cas9-mediated activation of CDH1 suppresses metastasis of breast cancer in rats

BACKGROUND Cancer is a life-threatening disease that affects approximately 18 million individuals worldwide. Breast cancer is the most common female neoplasm globally with more than 276,480 new cases of invasive breast cancer expected to be diagnosed in women in the U.S. alone in 2020. Genetic and epigenetic factors play role in the carcinogenesis and progression of this disease. In this study, MCF-7 adenocarcinoma cells were transfected with CRISPR/Cas9 plasmid to either knock out CDK11 or to activate CDH1. Treated cells were allografted into the mammary glands of female rats (150­190 g, 6­8 weeks) to evaluate the capability of these cells to control cancer progression and metastasis. RESULTS qPCR data revealed a significant downregulation of CDK11 and upregulation of CDH1. Cell cycle analysis and apoptosis assays indicated the knockout of CDK11 and simultaneous activation of CDH1 resulted in cell cycle arrest at G2/M phase and accumulation of cells at G2. Meanwhile, the percentage of cells that underwent late apoptosis increased in both genome editing hits. Histopathological sectioning data indicated that untransfected MCF-7 cells were capable of developing tumors in the mammary gland and initiation g angiogenesis. Transfected cells significantly restricted cancer cell infiltration/invasion by minimally localizing tumors and inhibiting angiogenesis. CONCLUSIONS Although further investigation is needed, the present data indicate the potentiality of using CRISPR/Cas9-based therapy as a promising approach to treat breast cancer. Impact: these data indicate targeting cancer-related genes via any genome editing tool might represent a novel approach to combat cancer.

miR-206 inhibits the proliferation and invasion of estrogen-induced ER-α36-positive gastric cancer BGC-823 cells by targeting CDK14 / 中国肿瘤生物治疗杂志

@#[摘 要] 目的：探讨miR-206对雌激素诱导的ER-α36阳性胃癌（gastric cancer, GC）细胞BGC-823增殖和侵袭的影响及其相关机制。方法: 用不同浓度（1、10和100 pmol/L）的雌二醇（estradiol，E2）刺激ER-α36阳性BGC-823细胞后，用qPCR法检测miR-206表达水平，MTT法和Transwell实验分别检测细胞的增殖和侵袭能力，WB法检测细胞中CDK14的表达。将miR-206 mimic、miR-NC、pcDNA-CDK14、pcDNA-vector等转染ER-α36阳性BGC-823细胞，并给予100 pmol/L的E2处理后，用MTT法和Transwell小室法分别检测细胞的增殖和侵袭能力，WB法检测细胞中CDK14的表达。用双荧光素酶报告基因实验验证miR-206与CDK14之间的靶向关系。结果: E2能显著降低ER-α36阳性BGC-823细胞中miR-206表达水平（P<0.05或P<0.01）、增强细胞的增殖和侵袭能力（P<0.05或P<0.01）、上调细胞中CDK14的表达水平（P<0.01）。过表达miR-206能显著降低E2诱导的ER-α36阳性BGC-823细胞的增殖和侵袭能力（均P<0.01）。miR-206通过直接结合CDK14 mRNA的3'-UTR发挥抑制作用，从而负向调节CDK14的表达，进而抑制ER-α阳性BGC-823细胞的增殖和侵袭能力（均P<0.01）。结论: miR-206通过靶向CDK14从而抑制雌激素诱导的ER-α36阳性GC细胞的增殖和侵袭。

Selective inhibition of CDK4/6: A safe and effective strategy for developing anticancer drugs

The sustained cell proliferation resulting from dysregulation of the cell cycle and activation of cyclin-dependent kinases (CDKs) is a hallmark of cancer. The inhibition of CDKs is a highly promising and attractive strategy for the development of anticancer drugs. In particular, third-generation CDK inhibitors can selectively inhibit CDK4/6 and regulate the cell cycle by suppressing the G1 to S phase transition, exhibiting a perfect balance between anticancer efficacy and general toxicity. To date, three selective CDK4/6 inhibitors have received approval from the U.S. Food and Drug Administration (FDA), and 15 CDK4/6 inhibitors are in clinical trials for the treatment of cancers. In this perspective, we discuss the crucial roles of CDK4/6 in regulating the cell cycle and cancer cells, analyze the rationale for selectively inhibiting CDK4/6 for cancer treatment, review the latest advances in highly selective CDK4/6 inhibitors with different chemical scaffolds, explain the mechanisms associated with CDK4/6 inhibitor resistance and describe solutions to overcome this issue, and briefly introduce proteolysis targeting chimera (PROTAC), a new and revolutionary technique used to degrade CDK4/6.