Rabbit Anti-Human PTPRG Polyclonal antibody

The R5 subfamily of receptor-type protein tyrosine phosphatases (RPTPs) comprises PTPRZ and PTPRG. A recent study on primary human glioblastomas suggested a close association between PTPRZ1 (human PTPRZ) expression and cancer stemness. However, the functional roles of PTPRZ activity in glioma stem cells have remained unclear. In the present study, we found that sphere-forming cells from the rat C6 and human U251 glioblastoma cell lines showed high expression levels of PTPRZ-B, the short receptor isoform of PTPRZ. Stable PTPRZ knockdown altered the expression levels of stem cell transcription factors such as SOX2, OLIG2, and POU3F2 and decreased the sphere-forming abilities of these cells. Suppressive effects on the cancer stem-like properties of the cells were also observed following the knockdown of PTPRG. Here, we identified NAZ2329, a cell-permeable small molecule that allosterically inhibits both PTPRZ and PTPRG. NAZ2329 reduced the expression of SOX2 in C6 and U251 cells and abrogated the sphere-forming abilities of these cells. Tumor growth in the C6 xenograft mouse model was significantly slower with the co-treatment of NAZ2329 with temozolomide, an alkylating agent, than with the individual treatments. These results indicate that pharmacological inhibition of R5 RPTPs is a promising strategy for the treatment of malignant gliomas.

We have used nested reverse transcription-PCR (RT-PCR) and PCR on genomic DNA to search for aberrations in the FHIT and PTPRG genes, both located in chromosomal band 3p14.2, in specimens from cytogenetically analyzed benign breast lesions (three samples with atypical hyperplasia and one with fibroadenosis) from two women belonging to breast cancer families. The transcription analysis showed that the FHIT gene was either not expressed or that its expression was dramatically reduced to a level not detectable by nested RT-PCR in the samples with atypical hyperplasia. Genomic analysis of exons 3 and 5 of FHIT and exon 12 of PTPRG provided evidence that these DNA segments were homozygously deleted in the majority of the cells. These data are in line with the histopathological features and cytogenetic findings in the three samples; none contained normal parenchyma, and all had chromosomal aberrations involving band 3p14, RT-PCR analysis of the fibroadenosis specimen, which had a normal karyotype, detected the expected 856-bp fragment as well as an additional alternative transcript variant of FHIT with 1014 bp, The additional 158-bp sequence, which may add 38 amino acids to the NH2-terminal part of the previously described FHIT protein, was inserted between exons 4 and 5 and seems to be a new exon located in intron 4 of FHIT.