ABSTRACT
【Objective】 To investigate the impact of long non-coding RNA (lncRNA) FGD5-AS1 on the malignant biolo-goical behavior of bladder cancer (BC) cells by regulating micro RNA (miR)-129-5p/cyclin dependent kinase 6 (CDK6) axis. 【Methods】 Human BC cell line T24 was cultured from tumor tissue and paracancerous tissue of 105 patients with confirmed BC. The expressions of FGD5-AS1, miR-129-5p and CDK6 mRNA in tissue samples and T24 cells were detected with RT-qPCR. T24 cells were randomly divided into control group, si-NC group, si-FGD5-AS1 group, si-FGD5-AS1+inhibitor NC group and si-FGD5-AS1+miR-129-5p inhibitor group. The cell viability, migration, invasion andapoptosis were detected with CCK-8, Wound healing test, Transwell assay and flow cytometry, respectively. The expressions of Bax, Bcl-2, Caspase3 and CDK6 were detected with Western blot. The relationship between FGD5-AS1 and miR-129-5p, between miR-129-5p and CDK6 were verified with double luciferase reporter gene experiment. 【Results】 FGD5-AS1 and CDK6 mRNA were highly expressed in BC tissue, while miR-129-5p was lowly expressed (P<0.05). After FGD5-AS1 silencing, the expression of FGD5-AS1,A450 value, cell scratch healing rate, cell invasion number, and expressions of Bcl-2 and CDK6 were significantly lower, while the apoptosis rate and expressions of miR-129-5p, Bax and Caspase3 were significantly higher (P<0.05). Inhibition of miR-129-5p expression reversed the effects of FGD5-AS1 silencing on various indexes of BC cells (P<0.05). FGD5-AS1 negatively regulated the expression of miR-129-5p, and miR-129-5p negatively regulated the expression of CDK6. 【Conclusion】 Silencing FGD5-AS1 may inhibit the expression of CDK6 protein by up-regulating miR-129-5p, thus inhibiting the proliferation, migration and invasion of BC cells and promoting cell apoptosis.
ABSTRACT
Natural products are an important source for the development of antitumor lead compounds, but the pharmacological effects and regulatory mechanisms of natural products in osimertinib resistance in non-small cell lung cancer (NSCLC) are not well understood. The natural product ligustroflavone was used as the research object to analyze its efficacy in osimertinib-resistant NSCLC cells by cell proliferation assay and cell cycle detection. The potential targets of ligustroflavone in osimertinib-resistant NSCLC cells were screened by public databases and bioinformatics, molecular docking and microscale thermophoresis were used to identify the interaction between privet and target molecules. Western blot was used to detect the effect of privet on the target molecules and their downstream pathways. Ligustroflavone reduced the proliferation of osimertinib-resistant NSCLC cells, and could arrest the cell cycle. Cyclin-dependent kinase 6 (CDK6) was the potential target of ligustroflavone in osimertinib-resistant NSCLC cells. Ligustroflavone inhibited the activation of CDK6-Rb axis. Together, ligustroflavone could regulate osimertinib resistance in NSCLC cells by binding cell cyclin-related molecules. This study provides a theoretical basis for the targeted drug resistance of NSCLC with natural products, and also provides a new idea for the development of clinical drug combination.
ABSTRACT
Cyclin-dependent kinase 4/6 inhibitors represent a major advance in breast cancer treatment, emerging as the standard of care of the initial treatment of hormone receptor-positive and HER2-negative metastatic breast cancer. Their activity in this subset of patients leads to interest in their use in the adjuvant and neoadjuvant settings. This case report presents a real-life case of cyclin-dependent kinase 4/6 inhibitors use in a patient initially considered to have stage IV luminal HER2-negative breast cancer with liver metastasis. The discrepancy of treatment response between the breast tumor and liver node led to a repetition of the liver biopsy, which revealed metastasis of a neuroendocrine tumor of unknown primary. The breast tumor showed a partial response, and the initial therapeutic strategy was then redefined for curative intent. While cyclin-dependent kinase 4/6 inhibitors are not yet approved for clinical practice in the neo / adjuvant treatment of hormone receptor-positive breast cancer, this case report portrays a successful example of its application in a neoadjuvant setting.
Subject(s)
Humans , Female , Adult , Breast Neoplasms , Carcinoma/pathology , Cyclin-Dependent Kinase 4/therapeutic use , Cyclin-Dependent Kinase 6/therapeutic use , Neuroendocrine Tumors , Liver/abnormalities , Neoplasm MetastasisABSTRACT
Objective@#To study the effects of miR-497 and CDK6 on the growth of laryngeal squamous cell carcinoma (LSCC).@*Methods@#The expressions of CDK6 mRNA in fresh LSCC specimens, the adjacent normal mucosa of LSCC, and cell lines of LSCC were detected with quantitative real time polymerase chain reaction, pcDNA3.1(+) CDK6 plasmids were respectively transfected into the LSCC cells, and MTT assay and clone formation assay were performed to evaluate the growth of LSCC cells. Flow cytometry was employed for cell cycle analysis. SPSS17.0 software was used to analyze the data.@*Results@#CDK6 was highly expressed in LSCC(t=14.01, P=0.009) and the overall survival rate of the patients with high CDK6 expression was less than that with low CDK6 expression, with a significant difference (HR=3.236, P<0.001). Double luciferase reporter gene analysis showed that fluorescence activity in wild type CDK6 group was significantly different from that in control group (P<0.01), while there was no significant difference in the fluorescence activity between mutant CDK6 group and control group (P>0.05). A490 values were respectively 0.42±0.14 (Mean±SD) in siRNA Hep-2 group, 0.51±0.13 in siRNA TU-212 group; 0.98±0.16 in control Hep-2 group and 1.17±0.20 in control TU-212 group. Colonies were 55±4 in siRNA Hep-2 group, 51±3 in siRNA TU-212 group, 108±6 in control Hep-2 group and 105±7 in control TU-212 group, namely, cell growth and clone formation ability in CDK6 siRNA group were significantly lower than those in the control group. Cells cycle was blocked in G0/G1 phase (G0/G1: 65.20%±10.12% in siRNA Hep-2 group; 63.42%±8.97% in siRNA TU-212 group; 45.31%±7.55% in control Hep-2 group; and 42.37%±7.28% in control TU-212 group), and cells decreased obviously in S phase (S: 25.39%±5.51% in siRNA Hep-2 group; 27.21%±5.43% in siRNA TU-212 group; 42.87%±6.85% in control Hep-2 group; and 44.76%±7.02% in control TU-212 group). Compared with miR-497 group, cell growth and clone formation ability in miR-497/CDK6 group were partly restored (all P<0.05).@*Conclusions@#CDK6 expression in LSCC is upregulated, functioning as an oncogene. High expression of CDK6 is a predictor for poor prognosis. miR-497, functioning as a tumor suppressor gene, inhibits the growth of LSCC by targeting CDK6.
ABSTRACT
Objective@#To understand the mechanism of chemotherapy resistance in nasopharyngeal carcinoma under hypoxic conditions through the perspective of protein SUMOylation modification.@*Methods@#Cobalt chloride (CoCl2) was used to establish the hypoxic model of human nasopharyngeal carcinoma CNE1 cells. Then, the cell cycle was detected by flow cytometry, and the expression level of small ubiquitin-related modifier(SUMO) and cyclin-dependent kinase 6 (CDK6) proteins were detected by western blotting. MTT assay was used to determine the median lethal dose (IC50) of cancer cells against cisplatin, and enzyme-linked immunosorbent assay (ELISA) was used to determine lactate dehydrogenase (LDH) level.@*Results@#The cell cycle of CNE1 induced by hypoxia was arrested in G0/G1 phase.The results of Western blot showed that the protein expression level of CDK6 in CNE1 cells was lower than that in the control group (0.83±0.25 vs. 0.43±0.21, t=14.67, P=0.003). The protein level of conjugated SUMO1 was significantly lower than that in the control group (2.69±0.48 vs. 1.38±0.31, t=17.22, P=0.001), while the level of free SUMO1 protein was significantly higher than that in the control group (2.01±0.43 vs. 2.60±0.59, t=15.45, P=0.002).The LC50 of CNE1 cells in the control group was significantly lower than that in the hypoxic group (29.44 μg/ml vs. 97.72 μg/ml, t=12.79, P=0.001). After CNE1 cells received 50 μg/ml cisplatin for 48 h, the LDH content in the supernatant of the control group was significantly higher than that in the hypoxic group ((541.49±64.59) ng/ml vs. (234.67±41.03) ng/ml, t=11.94, P=0.007)). The apoptosis rate of CNE1 cells in the control group was significantly higher than that in the hypoxic group ((76.64±5.37)% vs. (32.84±4.77) ng/ml, t=8.49, P=0.003)).@*Conclusion@#Hypoxia can dissociate the covalent modification of CDK6 and SUMO1, inhibit cell cycle and increase the chemotherapy resistance of nasopharyngeal carcinoma.
ABSTRACT
Endocrine therapy is one of the standard treatment options for breast cancer which plays an important role in treating patients with estrogen receptor (ER) positive and human epidermal growth factor receptor 2 (HER2) negative breast cancer.However,some patients develop resistance during therapy due to factors such as tumor heterogeneity,which is particularly acute in the treatment of advanced breast cancer.Based on aiming at a rational and effective treatment,some clinical trials recently have demonstrated that compared to endocrine therapy alone,cyclin-dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy can significantly improve the prognosis of ER-positive,HER2-negative advanced breast cancer.Its main products are Palbociclib,Ribociclib and Abemaciclib.This review mainly focuses on the mechanism and related clinical trials of CDK4/6 inhibitor inhibitors in ER-positive,HER2-negative advanced breast cancer.
ABSTRACT
Objective To observe the expression of P21 and CDK6 in cervical squamous cell carcinoma,and to investigate the relationship between their expression and cervical squamous cell carcinoma.Methods The expression of CDK6 and P21 in 100 cases of cervical squamous cell carcinoma,20 cases of cervical CIN lesions and 20 cases of normal cervical tissues were detected by immunohistochemical ABC method,and the relationship between them and tumor differentiation,invasion depth,lymph node metastasis and clinical stage were analyzed.Results The expression rates of P21 and CDK6 in cervical squamous cell carcinoma tissues were significantly higher than those in CIN lesions and normal cervical tissues;The low expression of P21 was associated with the depth of tumor invasion,lymph node metastasis and clinical stage (P＜0.05),and was not associated with the degree of tumor differentiation (P＞0.05);The high expression of CDK6 was associated with tumor differentiation,invasion depth,lymph node metastasis and clinical stage (P＜0.05).Conclusion The abnormal expression of P21 and CDK6 may play an important role in the occurrence and development of cervical squamous cell carcinoma,and the two may have a certain significance in the prognosis of cervical squamous cell carcinoma.