T790M-negative patients with EGFR mutation-positive NSCLC are more likely to benefit from nivolumab after EGFR-TKI treatment, possibly as a result of a higher PD-L1 expression level, than are T790M-positive patients.
Forkhead box Q1 (FOXQ1) is a member of the forkhead transcription factor family, and it has recently been proposed to participate in gastric acid secretion and mucin gene expression in mice. However, the role of FOXQ1 in humans and especially in cancer cells remains unknown. We found that FOXQ1 mRNA is overexpressed in clinical specimens of colorectal cancer (CRC; 28-fold/colonic mucosa). A microarray analysis revealed that the knockdown of FOXQ1 using small interfering RNA resulted in a decrease in p21 CIP1/WAF1 expression, and a reporter assay and a chromatin immunoprecipitation assay showed that p21 was one of the target genes of FOXQ1. knockdown of H1299/FOXQ1 cells increased tumor growth, suggesting that FOXQ1 promotes tumor growth independent of p21. Microarray analysis of H1299/EGFP and H1299/FOXQ1 revealed that FOXQ1 overexpression upregulated several genes that have positive roles for tumor growth, including VEGFA, WNT3A, RSPO2, and BCL11A. CD31 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining of the tumor specimens showed that FOXQ1 overexpression mediated the angiogenic and antiapoptotic effect in vivo. In conclusion, FOXQ1 is overexpressed in CRC and enhances tumorigenicity and tumor growth presumably through its angiogenic and antiapoptotic effects. Our findings show that FOXQ1 is a new member of the cancer-related FOX family.
Background:Although a high level of thymidylate synthase (TS) expression in malignant tumours has been suggested to be related to a reduced sensitivity to the antifolate drug pemetrexed, no direct evidence for such an association has been demonstrated in non-small cell lung cancer (NSCLC). We have now investigated the effect of TS overexpression on pemetrexed sensitivity in NSCLC cells.Methods:We established NSCLC cell lines that stably overexpress TS and examined the effects of such overexpression on the cytotoxicity of pemetrexed both in vitro and in xenograft models. We further examined the relation between TS expression in tumour specimens from NSCLC patients and the tumour response to pemetrexed by immunohistochemical analysis.Results:The sensitivity of NSCLC cells overexpressing TS to the antiproliferative effect of pemetrexed was markedly reduced compared with that of control cells. The inhibition of DNA synthesis and induction of apoptosis by pemetrexed were also greatly attenuated by forced expression of TS. Furthermore, tumours formed by TS-overexpressing NSCLC cells in nude mice were resistant to the growth-inhibitory effect of pemetrexed observed with control tumours. Finally, the level of TS expression in tumours of non-responding patients was significantly higher than that in those of responders, suggestive of an inverse correlation between TS expression and tumour response to pemetrexed.Conclusion:A high level of TS expression confers a reduced sensitivity to pemetrexed. TS expression is thus a potential predictive marker for response to pemetrexed-based chemotherapy in NSCLC patients.
PURPOSE Although gene expression profiling is a promising diagnostic technique to determine the tissue of origin for patients with cancer of unknown primary site (CUP), no clinical trial has evaluated yet site-specific therapy directed by this approach compared with empirical chemotherapy. We therefore performed a randomized study to assess whether such site-specific therapy improves outcome compared with empirical chemotherapy in previously untreated patients with CUP. PATIENTS AND METHODS Comprehensive gene expression profiling was performed by microarray analysis, and an established algorithm was applied to predict tumor origin. Patients with CUP were randomly assigned (1:1) to receive standard site-specific therapy or empirical paclitaxel and carboplatin (PC). The primary end point was 1-year survival rate. RESULTS One hundred thirty patients were randomly assigned and had sufficient biopsy tissue for molecular analysis. Efficacy analysis was performed for 50 and 51 patients in the site-specific therapy and empirical PC arms, respectively. Cancer types most commonly predicted were pancreatic (21%), gastric (21%), and lymphoma (20%). The 1-year survival rate was 44.0% and 54.9% for site-specific treatment and empirical PC ( P = .264), respectively. Median overall and progression-free survival were 9.8 and 5.1 months, respectively, for site-specific treatment versus 12.5 and 4.8 months for empirical PC ( P = .896 and .550, respectively). Median overall survival (16.7 v 10.6 months; P = .116) and progression-free survival (5.5 v 3.9 months; P = .018) were better for predicted more-responsive than less-responsive tumor types. CONCLUSION Site-specific treatment that was based on microarray profiling did not result in a significant improvement in 1-year survival compared with empirical PC, although prediction of the original site seemed to be of prognostic value.
Prodromal angina occurring shortly before the onset of infarction, but not previous angina itself, has a beneficial effect on long-term prognosis after infarction, suggesting a relation to ischemic preconditioning.
Background:MET is a receptor tyrosine kinase (RTK) whose gene is amplified in various tumour types. We investigated the roles and mechanisms of RTK heterodimerisation in lung cancer with MET amplification.Methods:With the use of an RTK array, we identified phosphorylated RTKs in lung cancer cells with MET amplification. We examined the roles and mechanisms of action of these RTKs with immunoprecipitation, annexin V binding, and cell migration assays.Results:We identified epidermal growth factor receptor (EGFR), human EGFR (HER)2, HER3, and RET in addition to MET as highly phosphorylated RTKs in lung cancer cells with MET amplification. Immunoprecipitation revealed that EGFR, HER2, HER3, and RET each formed a heterodimer exclusively with MET and that these associations were markedly reduced in extent by treatment with a MET kinase inhibitor. RNA interference-mediated depletion of EGFR, HER2, or HER3 induced apoptosis in association with inhibition of AKT and ERK signalling pathways, whereas depletion of HER2 or RET inhibited both cell migration and STAT3 signalling.Conclusion:Our data suggest that heterodimers of MET with EGFR, HER2, HER3, or RET have differential roles in tumour development, and they provide new insight into the function of trans-phosphorylated RTKs as heterodimerisation partners of MET in lung cancer with MET amplification.
The epithelial mesenchymal transition (EMT) has emerged as a pivotal event in the development of the invasive and metastatic potentials of cancer progression. Sorafenib, a VEGFR inhibitor with activity against RAF kinase, is active against hepatocellular carcinoma (HCC); however, the possible involvement of sorafenib in the EMT remains unclear. Here, we examined the effect of sorafenib on the EMT. Hepatocyte growth factor (HGF) induced EMT-like morphologic changes and the upregulation of SNAI1 and N-cadherin expression. The downregulation of E-cadherin expression in HepG2 and Huh7 HCC cell lines shows that HGF mediates the EMT in HCC. The knockdown of SNAI1 using siRNA canceled the HGF-mediated morphologic changes and cadherin switching, indicating that SNAI1 is required for the HGF-mediated EMT in HCC. Interestingly, sorafenib and the MEK inhibitor U0126 markedly inhibited the HGF-induced morphologic changes, SNAI1 upregulation, and cadherin switching, whereas the PI3 kinase inhibitor wortmannin did not. Collectively, these findings indicate that sorafenib downregulates SNAI1 expression by inhibiting mitogen-activated protein kinase (MAPK) signaling, thereby inhibiting the EMT in HCC cells. In fact, a wound healing and migration assay revealed that sorafenib completely canceled the HGF-mediated cellular migration in HCC cells. In conclusion, we found that sorafenib exerts a potent inhibitory activity against the EMT by inhibiting MAPK signaling and SNAI1 expression in HCC. Our findings may provide a novel insight into the anti-EMT effect of tyrosine kinase inhibitors in cancer cells.
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