The genetic etiology of hereditary breast cancer has not been fully elucidated. Although germline mutations of high-penetrance genes such as BRCA1/2 are implicated in development of hereditary breast cancers, at least half of all breast cancer families are not linked to these genes. To identify a comprehensive spectrum of genetic factors for hereditary breast cancer in a Chinese population, we performed an analysis of germline mutations in 2,165 coding exons of 152 genes associated with hereditary cancer using next-generation sequencing (NGS) in 99 breast cancer patients from families of cancer patients regardless of cancer types. Forty-two deleterious germline mutations were identified in 21 genes of 34 patients, including 18 (18.2%) BRCA1 or BRCA2 mutations, 3 (3%) TP53 mutations, 5 (5.1%) DNA mismatch repair gene mutations, 1 (1%) CDH1 mutation, 6 (6.1%) Fanconi anemia pathway gene mutations, and 9 (9.1%) mutations in other genes. Of seven patients who carried mutations in more than one gene, 4 were BRCA1/2 mutation carriers, and their average onset age was much younger than patients with only BRCA1/2 mutations. Almost all identified high-penetrance gene mutations in those families fulfill the typical phenotypes of hereditary cancer syndromes listed in the National Comprehensive Cancer Network (NCCN) guidelines, except two TP53 and three mismatch repair gene mutations. Furthermore, functional studies of MSH3 germline mutations confirmed the association between MSH3 mutation and tumorigenesis, and segregation analysis suggested antagonism between BRCA1 and MSH3. We also identified a lot of low-penetrance gene mutations. Although the clinical significance of those newly identified low-penetrance gene mutations has not been fully appreciated yet, these new findings do provide valuable epidemiological information for the future studies. Together, these findings highlight the importance of genetic testing based on NCCN guidelines and a multi-gene analysis using NGS may be a supplement to traditional genetic counseling.
Objective:
Shikonin has inhibitory effects against nasopharyngeal carcinoma that are mediated through the apoptotic pathway. However, necroptosis signaling pathways may enable the elimination of apoptosis-resistant cancers when induced with targeted therapeutic agents. Thus, there is a need to clarify whether shikonin can cause necroptosis in nasopharyngeal carcinoma and to elucidate the underlying mechanisms.
Methods:
In this study, we used the nasopharyngeal carcinoma cell line 5-8F and a 5-8F xenograft mouse model to evaluate the anticancer effects of shikonin. The viability and morphology of cells treated with shikonin were evaluated using CCK-8 assay and transmission electron microscopy, respectively. In addition, the expression levels of RIPK1, RIPK3, and MLKL were analyzed by western blotting, and the activities of caspase-3 and caspase-8 and levels of reactive oxygen species (ROS) were assessed.
Results:
Shikonin exhibited a strong inhibitory effect on 5-8F cells in vitro and in vivo. The shikonin-treated 5-8F cells presented an electron-lucent cytoplasm, loss of plasma membrane integrity, and an intact nuclear membrane, indicating that shikonin induced necroptosis. Shikonin-induced cell death was inhibited by necrostatin-1. Moreover, RIPK1, RIPK3, and MLKL were upregulated by shikonin in a dose-dependent manner. Furthermore, shikonin significantly inhibited tumor growth in the 5-8F xenograft mouse model.
Conclusion:
Shikonin induced 5-8F cell death via increased ROS production and the upregulation of RIPK1/RIPK3/MLKL expression, resulting in necroptosis. Thus, shikonin may represent a novel agent to treat nasopharyngeal carcinoma.
The study indicated that CYP3A4 is likely to be the major enzyme responsible for glycyrrhetinic acid metabolism in HLM while CYP2C9 and CYP2C19 are considerably less active. The results suggest that glycyrrhetinic acid has the potential to interact with a wide range of xenobiotics or endogenous chemicals that are CYP2C9, CYP2C19 and CYP3A4 substrates.
The combination chemotherapy of docetaxel and nedaplatin in the outpatient setting is well tolerated and useful as second-line chemotherapy for cisplatin-pretreated refractory metastatic/recurrent esophageal squamous cell carcinoma.
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