Expression of PAK4 in breast cancer and benign breast pathological changes / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the role of p21-activated kinase-4 (PAK4) in the occurrence, progression and metastasis of breast cancer.</p><p><b>METHOD</b>PAK4 expression was detected in 35 cases of normal breast, 22 breast cystic hyperplasia, 28 breast adenofibroma, 37 breast cancer (including 7 non-invasive cancer, 9 early invasive cancer and 21 invasive cancer) and 13 metastatic breast cancer tissues using immunohistochemistry for a comparison of PAK4 expression and distribution.</p><p><b>RESULTS</b>PAK4 was expressed mainly in the cytoplasm of the cancer cells, occasionally in the cell nuclei, and virtually not expressed in the matrix surrounding the breast cells. PAK4 positivity rates increased in the order of normal breast tissues, benign changes (including breast cystic hyperplasea and breast adenoma), breast cancer and metastatic cancer tissues; in the cancer tissues, the positivity rates increased in the order of non-invasive breast tumor, early invasive tumor and invasive tumor tissues.</p><p><b>CONCLUSION</b>PAK4 is closely correlated to the progression and metastasis of breast cancer and may become a new diagnostic and therapeutic target of breast cancer.</p>

Cloning of human PAK6 cDNA, preparation of anti-PAK6 polyclonal antibody and PAK6 expression in prostate cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the role of PAK6 in prostate cancer by cloning PAK6-N terminal sequence into E.coli and preparing its polyclonal rabbit antibody to detect PAK6 expression in prostate cancer.</p><p><b>METHODS</b>Based on human PAK6 cDNA sequence, we designed a pair of primers to amplify the PAK6-N terminal sequence by PCR. The PCR product was subcloned into the bacterial expression vector pGEX-4T-1 via EcoRI/XhoI sites, and the recombinant plasmids were identified by enzymatic cleavage followed by DNA sequence analysis. By transforming the expression vector into component E.coli BL21 cells, the GST-PAK6-N fusion protein was expressed with IPTG induction. Glutathione-Sepharose beads were used to purify GST- PAK6-N fusion protein. Anti-PAK6 polyclonal antibody was produced by immunizing rabbits with purified GST-PAK6 N-terminal fusion protein. Anti-PAK6 polyclonal antibody was purified by protein A beads and used for detection of PAK6 expression in 3 prostate cancer specimens.</p><p><b>RESULTS AND CONCLUSION</b>We cloned PAK6-N terminal gene fragment successfully, purified GST-PAK6 N-terminal fusion protein, and obtained polyclonal rabbit PAK6 antibody. Immunohistochemistry indicated that PAK6 expressed in the stroma instead of the cancer cells in prostate cancer. All of the 3 prostate cancer specimens showed positive staining in the stroma, suggesting that PAK6 may participate in the stroma-cancer cell interaction in prostate cancer.</p>