Vemurafenib downmodulates aggressiveness mediators of colorectal cancer (CRC): Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP), Protein Tyrosine Phosphatase 1B (PTP1B) and Transforming Growth Factor β (TGFβ)

2020 ◽  
Vol 401 (9) ◽  
pp. 1063-1069 ◽  
Author(s):  
Helon Guimarães Cordeiro ◽  
Alessandra Valéria de Sousa Faria ◽  
Carmen Veríssima Ferreira-Halder

AbstractColorectal Cancer (CRC) therapy confronts challenges as chemoresistance and side effects. Therefore, drugs with antitumor properties that downmodulate aggressiveness mediators are required. Studies have shown the relevance of Low Molecular Weight Protein Tyrosine Phosphatase (LMWPTP), Protein Tyrosine Phosphatase 1B (PTP1B), and Transforming Growth Factor β (TGFβ) in mediating proliferation, chemoresistance, and metastasis. In this study, we aimed to investigate the responsiveness of colorectal cancer lines (HT29 and HCT116) towards Vemurafenib and whether this treatment could modulate these aggressiveness mediators. Cytotoxicity Assays (MTT and Trypan Exclusion Test) were performed to evaluate the viability of HT29 and HCT116 cells treated with Vemurafenib. Western blotting was performed to analyze the amount and/or the activity of mediators (LMWPTP, PTP1B, TGFβ, SMAD3), and the immunoprecipitation was performed to evaluate LMWPTP activity. This study brought up novel aspects of Vemurafenib action in colorectal cancer, which can decrease the activity of protein tyrosine phosphatases (LMWPTP and PTP1B) and the TGFβ pathway, making them important in the CRC aggressiveness. By downmodulating colorectal cancer hallmarks, Vemurafenib appears as an interesting candidate for CRC therapeutic protocols.

Oncotarget ◽  
2015 ◽  
Vol 6 (10) ◽  
pp. 8300-8312 ◽  
Author(s):  
Elmer Hoekstra ◽  
Liudmila L. Kodach ◽  
Asha M. Das ◽  
Roberta R. Ruela-de-Sousa ◽  
Carmen V. Ferreira ◽  
...  

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 1742-P
Author(s):  
STEPHANIE M. STANFORD ◽  
MICHAEL A. DIAZ ◽  
JIWEN J. ZOU ◽  
ROBERT J. ARDECKY ◽  
ANTHONY PINKERTON ◽  
...  

2005 ◽  
Vol 187 (6) ◽  
pp. 2175-2181 ◽  
Author(s):  
Chaithanya Madhurantakam ◽  
Eerappa Rajakumara ◽  
Pooja Anjali Mazumdar ◽  
Baisakhee Saha ◽  
Devrani Mitra ◽  
...  

ABSTRACT The low-molecular-weight protein tyrosine phosphatase (LMWPTPase) belongs to a distinctive class of phosphotyrosine phosphatases widely distributed among prokaryotes and eukaryotes. We report here the crystal structure of LMWPTPase of microbial origin, the first of its kind from Mycobacterium tuberculosis. The structure was determined to be two crystal forms at 1.9- and 2.5-Å resolutions. These structural forms are compared with those of the LMWPTPases of eukaryotes. Though the overall structure resembles that of the eukaryotic LMWPTPases, there are significant changes around the active site and the protein tyrosine phosphatase (PTP) loop. The variable loop forming the wall of the crevice leading to the active site is conformationally unchanged from that of mammalian LMWPTPase; however, differences are observed in the residues involved, suggesting that they have a role in influencing different substrate specificities. The single amino acid substitution (Leu12Thr [underlined below]) in the consensus sequence of the PTP loop, C T GNICRS, has a major role in the stabilization of the PTP loop, unlike what occurs in mammalian LMWPTPases. A chloride ion and a glycerol molecule were modeled in the active site where the chloride ion interacts in a manner similar to that of phosphate with the main chain nitrogens of the PTP loop. This structural study, in addition to identifying specific mycobacterial features, may also form the basis for exploring the mechanism of the substrate specificities of bacterial LMWPTPases.


1998 ◽  
Vol 24 (3) ◽  
pp. 269-272 ◽  
Author(s):  
Marilia A. R. Buzalaf ◽  
E. M. Taga ◽  
JosÉ M. Granjeiro ◽  
Carmen V. Ferreira ◽  
ValÉRia A. Lourençā ◽  
...  

2017 ◽  
Vol 35 (6_suppl) ◽  
pp. 277-277
Author(s):  
Mari Ohtaka ◽  
Takashi Kawahara ◽  
Masato Yasui ◽  
Kouichi Uemura ◽  
Shuko Yoneyama ◽  
...  

277 Background: Protein tyrosine phosphorylation is an important event that is associated with the processes of cellular metabolism. The control of protein tyrosine phosphorylation is regulated by protein tyrosine kinases and protein tyrosine phosphatases (PTP). Thus, these proteins can control diverse processes like cell proliferation, adhesion, and migration. Recent studies revealed the importance of PTP in the oncogenic process, especially, the significance of low-molecular-weight protein tyrosine phosphatase (LMW-PTP) as a prognostic factor in early prostate cancer. In this study, we evaluated the significance of expression of LMW-PTP in metastatic hormone-sensitive prostate cancer (mHSPC) as a prognostic biomarker. Methods: We identified consecutive 48 men with mHSPC. The prostate cancer tissues obtained by needle biopsies were immunohistochemically stained for LMW-PTP. A pathologist blindly evaluated the expression of LMW-PTP and intensity of staining was classified into two groups, high (diffusely strongly positive) and low (at least focally weak-negative). The correlations between clinicopathological characteristics including age, initial PSA levels, Gleason scores, T stage, N stage, extend of disease on bone scan (EOD), and expression of LMW-PTP and overall survival (OS) were analyzed by multivariate analysis using cox proportional hazards regression model. Results: Median age was 70.0 years and median initial PSA level was 85.4 ng/mL. Gleason scores were 6-7 in 16 patients (33.4%) and 8-10 in 32 patients (66.6%). Clinical T stages were T2-3 disease in 34 patients (70.8%) and T4 in 14 patients (29.2%). Clinical N stages were N0 disease in 21 patients (43.7%) and N1 in 27 patients (56.3%). EOD grades were 0 in 13 patients (27.0%), 1 in 12 patients (25.0%), 2 in 14 patients (29.2%), 3 in 8 patients (16.7%), and 4 in 1 patient (2.1%). Multivariate analysis revealed that Gleason score (≥ 8 vs ≤ 7; HR: 5.795, 95%CI: 1.266-26.520, p = 0.024) and LMW-PTP expression (high vs low; HR: 2.736, 95%CI: 1.035-7.232, p = 0.042) were independent prognostic factors for OS. Conclusions: LMW-PTP might be a potential biomarker to predict overall survival for men with mHSPC.


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