Reduced expression of protein tyrosine phosphatase gamma in lung and ovarian tumors

Niekerk, Catharina C. van; Poels, L. G.

doi:10.1016/s0304-3835(98)00344-9

Cited by 31 publications

(28 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the chromosomal location of the PTPg gene (3p14.2) and studies showing loss of heterozygosity of the gene in kidney tumors (Lubinski et al, 1994), PTPg has been implicated as a candidate tumor suppressor gene. More recently, PTPg expression levels were shown to be reduced in ovarian and lung tumors (van Niekerk and Poels, 1999). Our previous results showed lower PTPg mRNA expression levels in diethylstilbestrol-induced kidney tumors in hamsters than in normal hamster kidney (Lin et al, 1994).…”

Section: Introductionmentioning

confidence: 94%

Function analysis of estrogenically regulated protein tyrosine phosphatase γ (PTPγ) in human breast cancer cell line MCF-7

et al. 2003

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 94%

Function analysis of estrogenically regulated protein tyrosine phosphatase γ (PTPγ) in human breast cancer cell line MCF-7

et al. 2003

View full text Add to dashboard Cite

“…1, 2). The PTPRG gene is localized at human chromosome 3p21, a hot spot for deletion in breast cancer, and expression of PTPRG is reduced in lung, ovarian, and breast tumors, suggesting its potential to function as a tumor suppressor (LaForgia et al 1991;Panagopoulos et al 1996;van Niekerk and Poels 1999;Vezzalini et al 2007). In addition, the PTPRG gene has been shown to play a role as an estrogen-regulated tumor suppressor (Liu et al 2002).…”

Section: Discussionmentioning

confidence: 99%

Identification of PTPN23 as a novel regulator of cell invasion in mammary epithelial cells from a loss-of-function screen of the ‘PTP-ome'

Lin¹,

Aranda²,

Muthuswamy³

et al. 2011

Genes Dev.

View full text Add to dashboard Cite

We used an RNAi-mediated loss-of-function screen to study systematically the role of the protein tyrosine phosphatase (PTP) superfamily of enzymes in mammary epithelial cell motility in the absence or presence of the oncoprotein tyrosine kinase ERBB2. We report that although shRNAs directed against most of the PTP family were without effect, suppression of three PTPs-PRPN23, PTPRG, and PTPRR-enhanced cell motility. Furthermore, we found that suppression of PTPN23, but not PTPRG or PTPRR, induced cell invasion. Suppression of PTPN23 increased E-cadherin internalization, impaired early endosome trafficking of E-cadherin, induced the expression of mesenchymal proteins, and caused cell scattering. The activity of SRC and b-catenin was elevated when PTPN23 was suppressed. Moreover, we identified SRC, E-cadherin, and b-catenin as direct substrates of PTPN23. Inhibition of SRC with the small molecular inhibitor SU6656 blocked the effects of PTPN23 depletion. These findings suggest that loss of PTPN23 may increase the activity of SRC and the phosphorylation status of the E-cadherin/b-catenin signaling complex to promote tumor growth and invasive behavior in breast cancer. In addition, our studies highlight functional specificity among PTPs and reveal new roles for PTPs in mammary epithelial cell biology.

show abstract

“…Though further investigation is apparently needed, the data may implicate the loss of both cPAcP and PTEN proteins are required to obtain the advanced PCa phenotype, the CR PCa. In parallel, it should also be noted for the remarkable similarity of functional interplay between PTPs and HER-2 family members and between phosphatase and Akt in other cancers for the survival of those cancer cells [126,144–154]. Based on the common theme of dephosphorylation of HER-2 and PIP3s by cPAcP in PCa, similar tissue-specific PTPs and also the ubiquitous protein phosphatases such as PTEN, PP2A and PHLPP can potentially be identified and developed as therapeutic targets for their respective carcinoma.…”

Section: Perspectivesmentioning

confidence: 99%

Cellular prostatic acid phosphatase, a PTEN-functional homologue in prostate epithelia, functions as a prostate-specific tumor suppressor

Muniyan

Ingersoll

Batra

et al. 2014

Biochimica et Biophysica Acta (BBA) - Reviews on Cancer

View full text Add to dashboard Cite

The inactivation of tumor suppressor genes (TSGs) plays a vital role in the progression of human cancers. Nevertheless, those ubiquitous TSGs have been shown with limited roles in various stages of diverse carcinogenesis. Investigation on identifying unique TSG, especially for early stage of carcinogenesis, is imperative. As such, the search for organ-specific TSGs has emerged as a major strategy in cancer research. Prostate cancer (PCa) has the highest incidence in solid tumors in US males. Cellular prostatic acid phosphatase (cPAcP) is a prostate-specific differentiation antigen. Despite intensive studies over the past several decades on PAcP as a PCa biomarker, the role of cPAcP as a PCa-specific tumor suppressor has only recently been emerged and validated. The mechanism underlying the pivotal role of cPAcP as a prostate-specific TSG is, in part, due to its function as a protein tyrosine phosphatase (PTP) as well as a phosphoinositide phosphatase (PIP), an apparent functional homologue to Phosphatase and tensin homolog (PTEN) in PCa cells. This review is focused on discussing the function of this authentic prostate-specific tumor suppressor and the mechanism behind the loss of cPAcP expression leading to prostate carcinogenesis. We review other phosphatases’ roles as TSGs which regulate oncogenic PI3K signaling in PCa and discuss the functional similarity between cPAcP and PTEN in prostate carcinogenesis.

show abstract

Reduced expression of protein tyrosine phosphatase gamma in lung and ovarian tumors

Cited by 31 publications

References 18 publications

Function analysis of estrogenically regulated protein tyrosine phosphatase γ (PTPγ) in human breast cancer cell line MCF-7

Function analysis of estrogenically regulated protein tyrosine phosphatase γ (PTPγ) in human breast cancer cell line MCF-7

Identification of PTPN23 as a novel regulator of cell invasion in mammary epithelial cells from a loss-of-function screen of the ‘PTP-ome'

Cellular prostatic acid phosphatase, a PTEN-functional homologue in prostate epithelia, functions as a prostate-specific tumor suppressor

Contact Info

Product

Resources

About