Anti-PDPN monoclonal antibody, clone SUE5F21

To investigate the role of podoplanin (PDPN) expression in invasive ductal carcinoma of the pancreas (IDCP) in humans. Tumor samples were obtained from 95 patients with IDCP. Immunohistochemical staining was done to evaluate the expression of PDPN in cancer tissues. PDPN was detected predominantly in stromal fibroblasts, stained with alpha-smooth muscle actin. The cutoff value of PDPN-positive areas was calculated according to a histogram. There was no significant difference in clinicopathologic factors between patients with high vs. those with low PDPN expression. The high PDPN group showed significantly poorer disease-free and disease-specific survival rates than the low PDPN group. Among patients from the high PDPN group, those with lymph node metastases and those with a tumor larger than 20 cm in diameter had significantly poorer prognoses than similar patients from the low PDPN group. Multivariate Cox proportional hazards analysis indicated that a high expression of PDPN was an independent risk factor for disease-specific survival. PDPN expression in cancer-related fibrotic tissues is associated with a poor prognosis, especially in patients with large tumors or lymph node metastases.

Objective: Podoplanin (PDPN) mediates tumor cell migration and invasion, which phenomena might also play a role in severe rheumatoid arthritis (RA). Therefore, the precise cellular distribution of PDPN and it's relationships with inflammation was studied in RA treated with biologic disease-modifying anti-rheumatic drugs (DMARD) or conventional DMARDs (cDMARD). Methods: PDPN+ cells were immunostained by NZ-1 mAb, and scored (3+; >50%/ area, 2+; 20%-50%, 1+; 5%-20%, 0: <5%) in synovial tissues from RA treated with biologic DMARDs (BIO, n=20) or cDMARD (n=20) for comparison with osteoarthritis (OA, n=5), followed by cell grading of inflammation and cell-typing. Results: Inflammatory synovitis score was 1.4 in both BIO and cDMARD, compared to only 0.2 in OA. PDPN+ cells were found in the lining layer (BIO 1.6, cDMARD 1.3, OA 0.2) and lymphoid aggregates (BIO 0.6, cDMRD 0.7, OA 0.2), and correlated with RA-inflammation in BIO- and cDMARD-groups in both area (r=0.7/0.9, r=0.6/0.7, respectively p<0.05). PDPN was expressed in CD68(+) type A macrophage-like and 5B5(+) type B fibroblast-like cells in the lining layer, and in IL-17(+) cells in lymphoid aggregates in RA. Conclusion: PDPN was markedly increased in the immunologically inflamed RA synovitis, which was surgically treated due to BIO- and cDMARD-resistant RA. PDPN may have potential of a new marker of residual arthritis in local joints for inflammation-associated severe RA.