Deficiency in VHR/DUSP3, a suppressor of focal adhesion kinase, reveals its role in regulating cell adhesion and migration.

Vaccinia H1-related phosphatase (VHR/DUSP3) is a member of the dual-specificity phosphatase family. Deregulation of VHR is observed in various malignant diseases. We identified focal adhesion kinase (FAK) as a VHR-interacting molecule. Over-expression of VHR decreased tyrosine phosphorylation of FAK and decreasing VHR promoted FAK tyrosine phosphorylation. In vitro assays proved that recombinant VHR directly dephosphorylated FAK and paxillin. VHR-knockout mice did not have obvious abnormality; however, VHR-knockout cells showed decreased expression of integrins and FAK but stronger FAK and paxillin phosphorylation upon attachment to fibronectin. Additionally, VHR-knockout fibroblast and lung epithelial cells had elevated ligand-induced epidermal growth factor receptor (EGFR) phosphorylation. Inducible expression of VHR suppressed directional cell migration, and VHR deficiency resulted in a higher cell migratory ability. VHR-knockout cells have stronger FAK phosphorylation in cell adhesions, long-lasting trailing ends and slower turnover of focal adhesions. These collective data indicate that VHR is a FAK phosphatase and participates in regulating the formation and disassembly of focal adhesions.

A KRAS mutation status-stratified randomized phase II trial of gemcitabine and oxaliplatin alone or in combination with cetuximab in advanced biliary tract cancer.

BACKGROUND: Previous clinical trials have not proved that adding epidermal growth factor receptor inhibitors to chemotherapy confers a survival benefit for patients with advanced biliary tract cancer (ABTC). Whether the KRAS mutation status of tumor cells confounded the results of past studies is unknown. PATIENTS AND METHODS: ABTC patients stratified by KRAS status, Eastern Cooperative Oncology Group performance status, and primary tumor location were randomized 1 : 1 to receive GEMOX (800 mg/m(2) gemcitabine and 85 mg/m(2) oxaliplatin) or C-GEMOX (500 mg/m(2) cetuximab plus GEMOX) every 2 weeks. The primary end point was objective response rate (ORR). RESULTS: The study enrolled 122 patients between December 2010 and May 2012 (62 treated with C-GEMOX and 60 with GEMOX). Compared with GEMOX alone, C-GEMOX was associated with trend to better ORR (27% versus 15%; P = 0.12) and progression-free survival (PFS, 6.7 versus 4.1 months; P = 0.05), but not overall survival (OS, 10.6 versus 9.8 months; P = 0.91). KRAS mutations, which were detected in 36% of tumor samples, did not affect the trends of difference in ORR and PFS between C-GEMOX and GEMOX. The two treatment arms had similar adverse events, except that more patients had skin rashes, allergic reactions, and neutropenia in the C-GEMOX arm. Of patients with C-GEMOX, the presence of a grade 2 or 3 skin rash was associated with significantly better ORR, PFS, and OS. CONCLUSIONS: Addition of cetuximab did not significantly improve the ORR of GEMOX chemotherapy in ABTC, although a trend of PFS improvement was observed. The trend of improvement did not correlate with KRAS mutation status. CLINICAL TRIALS NUMBER: This study is registered at ClinicalTrials.gov (NCT01267344). All patients gave written informed consent.

Prostate cancer screening practices: differences between clinic and private patients.

How often prostate cancer screening tests are conducted in general practice is unknown. It is known that at the primary care level, health care delivered to uninsured and Medicaid patients and to privately insured patients differs. We investigated the frequency of digital rectal examination and prostate-specific antigen testing in a clinic (an internal medicine clinic) and a faculty private practice population at The Mount Sinai Hospital over a period of one year. A total of 165 male patients over 40 years of age were asked to respond to a survey questionnaire; 142 interviews were completed (62 private and 80 clinic). Chart and computer database review were used to record the last serum prostate-specific antigen test performed. There was no difference in age distribution between the two groups. The private practice patients were more likely to be insured and college educated, whereas the clinic patients were more likely to have no more than an eighth-grade education and to receive Medicaid. The two groups did not differ in frequency of digital examination within the past year. Private patients were six times more likely than clinic patients to have had prostate-specific antigen screening and seven times more likely to receive both of the recommended prostate screening tests within the past year. Results also showed that 25% of all patients were not screened for cancer by digital rectal examination. Study of a larger population is recommended to further corroborate these findings.