Correlation between NGS panel-based mutation results and clinical information in colorectal cancer patients.

Early mutation identification guides patients with colorectal cancer (CRC) toward targeted therapies. In the present study, 414 patients with CRC were enrolled, and amplicon-based targeted next-generation sequencing (NGS) was then performed to detect genomic alterations within the 73 cancer-related genes in the OncoAim panel. The overall mutation rate was 91.5 % (379/414). Gene mutations were detected in 38/73 genes tested. The most frequently mutated genes were TP53 (60.9 %), KRAS (46.6 %), APC (30.4 %), PIK3CA (15.9 %), FBXW7 (8.2 %), SMAD4 (6.8 %), BRAF (6.5 %), and NRAS (3.9 %). Compared with the wild type, TP53 mutations were associated with low microsatellite instability/microsatellite stability (MSI-L/MSS) (P = 0.007), tumor location (P = 0.043), and histological grade (P = 0.0009); KRAS mutations were associated with female gender (P = 0.026), distant metastasis (P = 0.023), TNM stage (P = 0.013), and histological grade (P = 0.004); APC mutations were associated with patients <64 years of age at diagnosis (P = 0.04); PIK3CA mutations were associated with tumor location (P = 4.97e-06) and female gender (P = 0.018); SMAD4 mutations were associated with tumor location (P = 0.033); BRAF mutations were associated with high MSI (MSI-H; P = 6.968e-07), tumor location (P = 1.58e-06), and histological grade (P = 0.04). Mutations in 164 individuals were found to be pathogenic or likely pathogenic. A total of 26 patients harbored MSI-H tumors and they all had at least one detected gene mutation. Mutated genes were enriched in signaling pathways associated with CRC. The present findings have important implications for improving the personalized treatment of patients with CRC in China.

Relationship between CpG island methylation phenotype, microsatellite instability phenotype and mutation of KRAS, NRAS, and BRAF genes in colorectal cancer.

OBJECTIVE: CpG island methylation phenotype (CIMP) and microsatellite instability (MSI) are two different molecular mechanisms in colorectal cancer (CRC). Proto-oncogene KRAS, mutations in NRAS and BRAF play an important role in the formation of colorectal cancer. The correlation between the molecular typing of CIMP and MSI and the genes of KRAS, NRAS and BRAF was explored in this study. METHODS: A total of 110 paraffin-embedded specimens of colorectal cancer were collected from the Chinese People's Liberation Army Rocket Army Special Medical Center during the period from May 2017 to September 2018. CIMP were detected by DNA methylation quantitative PCR (Methylight). Mutations in KRAS, NRAS, and BRAF genes were detected by realtime fluorescence quantitative PCR (qPCR); MSI typing was detected by sequencing. RESULTS: Of the 110 colorectal cancer samples, 11 cases (10%) were CIMP-H, 92 cases (83.64%) were CIMP-L, and 7 cases (6.36%) were CIMP-0. 10 cases (9.09%) were MSI-H, and 100 cases (90.91%) were MSS and MSI-L. The mutation rates of KRAS, NRAS and BRAF genes were 50% (55 cases), 6.36% (7 cases) and 5.45% (6 cases), respectively. There was no significant correlation between CIMP group and MSI group (P > 0.05). Also, no significant differences were found in the mutations between the three subtypes of the CIMP group and the KRAS, NRAS genes (P > 0.05), while there was a statistically significant difference among the three subtypes of the BR and the BRAF gene mutations (P < 0.0001). There were no obvious differences between the three states of microsatellites and the mutations of KRAS and NRAS genes (P > 0.05), and the differences between them and BRAF gene mutations were statistically significant (P < 0.01). CONCLUSIONS: The BRAF gene mutation is closely related to the two types of CIMP and MSI, which may be an important part of the above two molecular mechanisms, and provide a reference for the treatment of the patients with CIMP-H and MSI-H.

miR-15b promotes epithelial-mesenchymal transition by inhibiting SMURF2 in pancreatic cancer.

The epithelial-mesenchymal transition (EMT) is a key developmental program that is often activated during cancer invasion and metastasis. We report here that silencing SMURF2 (SMAD specific E3 ubiquitin protein ligase 2) promoted EMT in HPDE6c7 normal pancreas cells and overexpression of SMURF2 inhibited TGF-ß-mediated EMT in the cells. Subsequent studies showed that SMURF2 was downregulated in pancreatic cancer tissues and it promoted mesenchymal-epithelial transition (MET) in pancreatic cancer cells as well as its expression negatively associated with gemcitabine-resistance, but it did not alter cell viability, cell cycle and cell senescence. In addition, we demonstrated that miR­15b degraded SMURF2 and its overexpression promoted EMT in pancreatic cancer, and its expression was associated with metastasis in the disease. Elucidating molecular mechanism of EMT in pancreatic cancer not only will help us to further understand the pathogenesis and progression of the disease, but also offers new targets for effective therapies.

miR-206 inhibits metastasis-relevant traits by degrading MRTF-A in anaplastic thyroid cancer.

Thyroid cancer develops from follicular or parafollicular thyroid cells. A higher proportion of anaplastic thyroid cancer has an adverse prognosis. New drugs are being used in clinical treatment. However, for advanced thyroid malignant neoplasm such as anaplastic thyroid carcinoma, the major impediment to successful control of the disease is the absence of effective therapies. Elucidating molecular mechanism of the disease will help us to further understand the pathogenesis and progression of the disease and offer new targets for effective therapies. In this study, we found that MRTF-A expression was upregulated in metastatic anaplastic thyroid cancer tissues, compared with primary cancer tissues and it promoted metastasis-relevant traits in vitro. miR-206 was negatively associated with metastasis in anaplastic cancer and it degraded MRTF-A by targeting its 3'-UTR in ARO anaplastic thyroid cancer cells. In addition, miR-206 overexpression inhibited invasion and migration and silencing miR-206-promoted migration and invasion in the cells. Important, restoration of MRTF-A could abrogate miR-206-mediated migration and invasion regulation. Thus, we concluded that miR-206 inhibited invasion and metastasis by degrading MRTF-A in anaplastic thyroid cancer.

[Expression of cyclin D1 in cervical intraepithelial neoplasia and squamous cell carcinoma and its relationship with HPV16 E7 gene].

OBJECTIVE: To investigate the expression of cyclin D1 in cervical intraepithelial neoplasia (CIN) and squamous cell carcinoma and its relationship with human papillomavirus 16 (HPV16) E7 gene expression. METHODS: Both SiHa and Hcc94 cell lines were obtained from cervical epithelial cells of squamous cell carcinoma. E6/E7 gene was silent in Hcc94 cell line.Expression levels of cyclin D1 mRNA and protein in CIN and squamous cell carcinoma were detected by QT-PCR and immunohistochemistry (IHC) respectively. SiRNA was constructed for targeting the promoter of HPV16 E7 and then transfected into SiHa cells to establish cm-16 line with stable silencing of E7. Control cell line B3 was obtained by blank plasmid transfection into SiHa cells. RT-PCR and Western blot were used to detect cyclin D1 mRNA and protein expression in the SiHa, B3, and cm-16 cells, respectively. RESULTS: Cyclin D1 was expressed in the basal cells of normal cervical squamous epithelia and the expression gradually decreased in the progression from CIN1 to CIN3. Squamous cell carcinoma showed negative or scattered expression of cyclin D1 (P<0.05). Both mRNA and protein of cyclin D1 in E7(+) SiHa cells were lower than those in cm-16 and Hcc94 cells. CONCLUSION: Squamous cell carcinoma with high HPV E7 expression shows low level of cyclin D1, suggesting that HPV16 E7 gene inhibits the expression of cyclin D1.