Lack of EGF receptor contributes to drug sensitivity of human germline cells

Breviscapine reverses doxorubicin resistance in breast cancer and its related mechanisms

BACKGROUND

Based on the effect of breviscapine (BRE) on reversing drug resistance of human breast cancer cell line MCF-7/doxorubicin (Dox), the mechanism was preliminarily explored.

METHODS

The methyl thiazolyl tetrazolium (MTT) method was introduced to detect inhibitory effect of Dox alone or in combination with BRE on MCF-7 (M) and MCF-7/Dox (MD) cells, and the inhibitory concentration (IC50 ) was obtained. Cell apoptosis and Dox concentration was assessed by flow cytometry. The drug resistance multiple and reversal fold were calculated. Western blot was performed to evaluate the expression of Bcl-2, Bax, EGFR, p-EGFR, P-gp, caspase-3, and cleaved-caspase-3 protein in cells. The efflux of Rho-123 was measured by flow cytometry and fluorescence microscopy.

RESULTS

The IC50 of Dox on MD and M cells was 16.67 and 0.71 μg/mL, respectively, with a drug resistance ratio of 23.48 times. The IC50 of Dox combined with BRE on MD cells was 5.62 μg/mL, with a reversal ratio of 2.97 times. BRE greatly enhanced Dox-induced apoptosis of MD cells. Bax and cleaved-caspase-3 (proapoptotic protein) expression were obviously increased, while Bcl-2 (antiapoptotic protein) expression was significantly decreased after BRE treatment. BRE inhibited EGFR activation and P-gp expression. BRE increased the intracellular accumulation of Dox in MD cells by P-gp.

CONCLUSION

BRE could increase the MD sensitivity to Dox via increasing Bax and cleaved-caspase-3 expression and inhibiting Bcl-2 expression, thereby promoting cell apoptosis. BRE reversed Dox resistance of MD cells by increasing Dox intracellular accumulation through inhibiting P-gp expression via EGFR.

Prevalence of germline mutations in cancer susceptibility genes in Chinese patients with renal cell carcinoma

Background

Germline pathogenic variants are estimated to affect 3-5% of patients with renal cell carcinoma (RCC). The identification of patients with hereditary RCC is important for cancer screening and treatment guidance.

Methods

Whole-exome sequencing (WES) (n=69) or gene panel sequencing containing 139 genes (n=54) related to germline cancer predisposition was used to analyze germline mutations in 123 patients with RCC admitted to Department of Urology, The Third Medical Center of Chinese PLA General Hospital. Chi-square test (χ²) was used to analyze relationship between clinicopathologic parameters and germline mutations.

Results

A total of 13 (10.57%) patients carried pathogenic or likely pathogenic germline mutations in 10 cancer predisposition genes, including VHL, FH, FLCN, SDHB, MUTYH, RAD51C, NBN, RAD50, FANCI, and FANCM. A total of 6 of these 10 cancer predisposition genes were associated with maintenance of genomic stability and DNA repair. Patients harboring pathogenic germline mutations tended to have an earlier RCC onset. The prevalence of deleterious mutations was higher in patients with bilateral or multifocal RCC compared to patients without bilateral or multifocal RCC. Patients with non-clear cell RCC (nccRCC) were significantly more likely to have RCC-associated gene mutations.

Conclusions

To our knowledge, this is the first report of pathogenic germline mutations in the FANCI and FANCM genes and heterozygous germline missense mutation in exon 5 of the FH gene c.563A>T:p.N188I in RCC. Young RCC patients, patients with bilateral or multifocal RCC, or patients with nccRCC are more likely to have pathogenic/potentially pathogenic germline mutations.

Octreotide enhances the sensitivity of the SKOV3/DDP ovarian cancer cell line to cisplatin chemotherapy in vitro

The present study aimed to investigate the effects of octreotide (OCT) on the reversal of resistance of cisplatin-resistant cancer cells and on enhancement of the cisplatin sensitivity of cancer cells. The 3-(4,5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide method and flow cytometry were used to investigate the effect of cisplatin, OCT or the combination of these two compounds on the proliferation and apoptosis of SKOV3/DDP cells. Real-time, quantitative RT-PCR was used to detect the mRNA expression of SSTR2, MDR1, MRP2, GST-π and EGFR in SKOV3/DDP cells following OCT treatment. At the concentration of 2.5-20 μg/ml, OCT significantly reduced the IC(50) value (P<0.05) and promoted apoptosis (P<0.05) in the SKOV3/DDP cells in response to cisplatin. The synergistic effect of OCT and cisplatin on SKOV3/DDP cell proliferation was observed. SSTR2 was expressed on the SKOV3/DDP cell surface. OCT increased GST-π expression (P<0.05) and reduced MRP2 and EGFR expression (P<0.05) in a dose-dependent manner. However, it had no effect on the expression of MDR1 (P>0.05). It is suggested that OCT inhibits ovarian cancer proliferation and promotes apoptosis, via the cell surface expression of SSRT2, and reverses cisplatin resistance through the inhibition of MRP2 and EGFR expression.

The expressions of bHLH gene HES1 and HES5 in advanced ovarian serous adenocarcinomas and their prognostic significance: a retrospective clinical study

Purpose

Notch signaling was recently found to be associated with prognosis of some cancers. The aim of the study is to investigate significance of the expression of HES1/HES5 protein, downstream effectors of Notch, in prognosis of the patients with advanced ovarian epithelial cancers.

Methods

Formalin-fixed, paraffin embedded tissues and clinic-pathological parameters from 61 patients with FIGO stage IIIc–IV ovarian serous adenocarcinoma were collected, the expression of HES1 and HES5 protein were immunohistochemically detected, and the association of HES1 and HES5 expression with survival of the patients were analyzed.

Results

The expressions of both HES1 and HES5 in adenocarcinoma were significantly higher than those in adenoma and normal control (χ² = 32.915, P = 0.000 and χ² = 46.863, P = 0.000 respectively). Overall survival and disease-free period were longer in HES1 low-expression patients (median 43.0 and 22.0 months) than those in high-expression patients (median 24.0 and 14.5 months). Of those, Overall survival period of patients with HES1 low-expression was significantly longer than that of those with high-expression (χ² = 4.049, P = 0.044). Univariate analysis and multivariate Cox regression model did not show that HES1 or HES5 expression was a factor associated with survival of advanced ovarian serous adenocarcinoma patients.

Conclusions

The expressions of bHLH gene HES1 and HES5 are increased in advanced ovarian serous adenocarcinomas, and HES1 high-expression probably is a potential poor prognostic factor for the patients.

Targeted therapy for epithelial ovarian cancer

Ovarian cancer is the leading cause of death in women with gynecological malignancies and overall survival for patients with advanced epithelial ovarian cancer (EOC) remains poor. The majority of patients recur after initial treatment. A strategy for improving outcome is to minimise recurrence via targeted therapy in patients after front-line therapy, or more appropriately as consolidation therapy. EOC represents an attractive target because of the biology of the disease and that the bulk of disease occurs in the peritoneal cavity. To initiate targeted therapy, a candidate target must be identified. Innovative approaches via targeted therapy to control metastatic residual EOC are currently under investigation. The targets are molecules and pathways, on which cancer cells depend to proliferate, invade, metastasise and prevent apoptosis. Potential targeted therapies include: proapoptototic therapy, suicide gene therapy, signal transduction, antiangiogenesis, immunotherapy and cytokine therapy. The utilisation of these targets in the clinic demands carefully conducted, well-coordinated but discovery-oriented translational research in the form of clinical trials that can quickly assess alternative strategies or combination of strategies that could result in clinical benefit. Therefore, targeted therapy for epithelial ovarian cancer, especially after complete response to standard regimens, represents a paradigm whose time has come to be nurtured.