Weighted gene co-expression network analysis and whole genome sequencing identify potential lung cancer biomarkers.

Background: Tuberculosis (TB) leads to an increased risk of lung cancer (LC). However, the carcinogenetic mechanism of TB remains unclear. We constructed gene co-expression networks and carried out whole-exome sequencing (WES) to identify key modules, hub genes, and the most recurrently mutated genes involved in the pathogenesis of TB-associated LC. Methods: The data used in this study were obtained from the Gene Expression Omnibus (GEO) and WES. First, we screened LC-related genes in GSE43458 and TB-related genes in GSE83456 by weighted gene co-expression network analysis (WGCNA). Subsequently, we screened differentially expressed genes related to LC and TB in GSE42834. We also performed WES of 15 patients (TB, n = 5; LC, n = 5; TB+LC, n = 5), constructed mutational profiles, and identified differences in the profiles of the three groups for further investigation. Results: We identified 278 hub genes associated with tumorigenesis of pulmonary TB. Moreover, WES identified 112 somatic mutations in 25 genes in the 15 patients. Finally, four common genes (EGFR, HSPA2, CECR2, and LAMA3) were confirmed in a Venn diagram of the 278 hub genes and the mutated genes from WES. KEGG analysis revealed various pathway changes. The PI3K-AKT signaling pathway was the most enriched pathway, and all four genes are included in this pathway. Thus, these four genes and the PI3K-AKT signaling pathway may play important roles in LC. Conclusion: Several potential genes and pathways related to TB-associated LC were identified, including EGFR and three target genes not found in previous studies. These genes are related to cell proliferation, colony formation, migration, and invasion, and provide a direction for future research into the mechanisms of LC co-occurring with TB. The PI3K-AKT signaling pathway was also identified as a potential key pathway involved in LC development.

WW45 inhibits breast cancer cell proliferation by the Hedgehog signaling pathway.

WW45 is a recently-discovered tumor suppressor gene. Overexpression of WW45 was found to significantly weaken proliferation and colony formation in a human breast cancer cell line, but the molecular mechanism of WW45's inhibitiory effect on proliferation was uncertain. It is a key transcription factor of the Hedgehog signaling pathway. In particular, the mechanism of Gli1's upstream proteins in regulating Gli1's nuclear import was not clear.We collected different breast cancer cell lines and detected WW45 and Gli1 expression by western blot. Gli1 expression was detected after WW45 was overexpressed in breast cancer cells. Gli1 and WW45 were transfected into breast cancer cells, and co-immunoprecipitation was used to detect whether the two proteins had physical interaction. We confirmed Gli1 blocks WW45-induced growth inhibition and colony formation in ZR-75-30 cells through cell functional experiments. Expression of WW45 negatively correlated with Gli1 expression in breast cancer cells. WW45 affected Gli1 intracellular localization though ww-PPxY/PsP interaction. Gli1 blocked WW45-induced growth inhibition and colony formation in ZR-75-30 cells. Our results strongly suggest that expression of WW45 negatively correlates with Gli1 expression in breast cancer cells. direct physical interaction occurred between WW45 and Gli1, and WW45 affected Gli1 intracellular localization though WW-PPxY/PsP interaction. Furthermore, Gli1 blocked WW45-induced breast cancer cell growth inhibition.

Bone morphogenetic protein 9 is a potential tumor suppressor in osteosarcoma.

Transforming growth factor-ß (TGF-ß) is known to promote tumor migration and invasion. Bone morphogenetic proteins (BMPs) are members of the TGF-ß family expressed in a variety of human carcinoma cell lines. Although accumulating evidence has shown that BMP9 plays important roles in the regulation of various cellular processes, the function of BMP9 in clinical osteosarcoma remains to be explored. In this study, BMP9 expression was analyzed in 55 osteosarcoma patient samples and their matching, distant non-cancerous tissues. And the roles of BMP9 in osteosarcoma cell proliferation, apoptosis and cell cycle were also examined. Our results showed that different expression level of BMP9 was detected in all osteosarcoma samples while no expression in normal tissues. Surprisingly, there was a negative association between the expression level of BMP9 and osteosarcoma grade, with low level of BMP9 being found in high histological grade osteosarcoma. Knockdown of BMP9 accelerated the proliferation of MG63, SaOS-2, and U2OS cells. BMP9 overexpression, however, induced cell apoptosis in U2OS cells. Together, these results indicated that BMP9 plays a pivotal role in osteosarcoma. Future studies defining the mechanism of BMP9 effect may lead to novel therapeutic approaches for osteosarcoma.