Effect and mechanism of Sitravatinib combined with Niraparib on proliferation,apoptosis and autophagy in mucosal melanoma cell lines / 基础医学与临床

Objective To investigate the effect of anti-angiogenic drug Sitravatinib combined with poly(adenosine diphosphate[ADP]-ribose)polymerase inhibitor(PARPi)Niraparib on mucosal melanoma cell lines and its possible mechanism.Methods The CCK8 assay was used to detect the maximal half inhibitory concentration(IC50)of Sitravatinib and Niraparib targeting at mucosal melanoma(MM)cell lines.CompuSyn was used to detect the Combination Index(CI)in different concentrations of the two drugs.Flow cytometry was used to detect the effect of drugs on cell apoptosis.Colony formation assay was used to detect the effect of drugs on cell proliferation.Western blot was used to detect the protein expressions and RT-qPCR was used to detect mRNA expression.Results CI values was respectively 0.19 and 0.15 for Sitravatinib(2 μmol/L)in combination with Niraparib(20 μmol/L)in a human vaginal maligant melanoma cell line(HMVII)and a metastasis inguinal lymph node of vulvar malignant melanoma cell line(GAK).Compared with the control group and single-drug groups,the cell proliferation of the combination group was significantly reduced(P＜0.05 or P＜0.01 or P＜0.001).The cell apoptosis rate was signifi-cantly increased(P＜0.01 or P＜0.001).The protein and mRNA expression of apoptosis-related biomarkers signifi-cantly increased(P＜0.001);In addition,the protein and mRNA expression of cell autophagy biomarkers signifi-cantly increased(P＜0.01 or P＜0.001).The protein expression of DNA damage marker significantly increased.Moreover,compared with the control group,The expression of radiation sensitive protein 51(RAD51)recombinase in the Sitravatinib single-drug group and combination group significantly reduced.As the dose of Sitravatinib gradu-ally increased up to 2 μmol/L,the protein and mRNA expression of RAD51 both significantly reduced(P＜0.05 or P＜0.01),the mRNA expression of BRCA1 and BRCA2 also significantly reduced(P＜0.05 or P＜0.01 or P＜0.001).Conclusions Sitravatinib combined with Niraparib inhibits the proliferation of mucosal melanoma cells,induces cell apoptosis and promotes autophagy.The mechanism is potentially related to the inhibition of ho-mology-dependent recombination repairs(HRR).

Progress of drug resistance mechanism of poly adenosine diphosphate ribose polymerase inhibitors and the combined medication in patients with ovarian cancer / 肿瘤研究与临床

Ovarian cancer seriously threats women's health. The emergence of poly adenosine diphosphate ribose polymerase inhibitor (PARPi) has broken the barrier for ovarian cancer treatment. PARPi has been widely used and along with it comes the problem of drug resistance. Fully understanding the drug resistance mechanism of PARPi is expected to be an important way to reverse PARPi resistance. The combination of PARPi and other drugs for ovarian cancer may expand the benefits of patients using PARPi. This article reviews the drug resistance mechanism of PARPi and combined medication.

Progress of hereditary breast cancer with breast cancer susceptibility gene 1/2 mutations / 肿瘤研究与临床

Hereditary breast cancer refers to malignant tumors caused by pathogenic germline mutations of breast cancer susceptibility genes (BRCA). At present, it is believed that BRCA1/2 genes are most closely related to the development of hereditary breast cancer. Mutation will lead to loss of normal function, instability of genome, and then lead to tumorigenesis. Especially for those with germline mutations, not only the risk of breast cancer will be greatly increased, but also the probability of ovarian cancer and other cancers will be increased. With the emergence and clinical application of poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors, BRCA1/2 genes have been regarded as new targets for the treatment of breast cancer. This article reviews the latest research of breast cancer with BRCA1/2 gene mutations.