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BackgroundInteractions between cancer cells and surrounding cancer-associated fibroblasts (CAFs) play an important role in cancer progression. Invasive ductal carcinoma (IDC) of the pancreas is characterized by abundant fibrous connective tissue called desmoplasia. Podoplanin (PDPN) is a lymphatic vessel marker (D2-40), and expression of PDPN by stromal CAFs has been reported to be a prognostic indicator in various types of cancer.MethodsExpression of PDPN in pancreatic IDCs was assessed by immunohistochemical examination in 105 patients who underwent pancreatic resection. Primary CAFs were established from pancreatic cancer tissue obtained by surgery. Quantitative reverse transcription-polymerase chain reaction and flow cytometric analysis were performed to investigate PDPN expression in CAFs. We sorted CAFs according to PDPN expression, and analyzed the functional differences between PDPN+ CAFs and PDPN– CAFs using indirect co-culture with pancreatic cancer cell lines. We also investigated the culture conditions to regulate PDPN expression in CAFs.ResultsPDPN expression in stromal fibroblasts was associated with lymphatic vessel invasion (P = 0.0461), vascular invasion (P = 0.0101), tumor size ≥3 cm (P = 0.0038), histological grade (P = 0.0344), Union for International Cancer Control classification T stage (P = 0.029), and shorter survival time (P < 0.0001). Primary CAFs showed heterogeneous PDPN expression in vitro. Moreover, migration and invasion of pancreatic cancer cell lines (PANC-1 and SUIT-2) were associated with PDPN expression in CAFs (P < 0.01) and expression of CD10, matrix metalloproteinase (MMP) 2, and MMP3. In cultured CAFs, PDPN positivity changed over time under several conditions including co-culture with cancer cells, different culture media, and addition of growth factor.ConclusionsPDPN-expressing CAFs enhance the progression of pancreatic IDC, and a high ratio of PDPN-expressing CAFs is an independent predictor of poor outcome. Understanding the regulation of the tumor microenvironment is an important step towards developing new therapeutic strategies.

IL-35 and IL-17, but not IL-27, may play important roles in the pathogenesis of periodontitis.

Most of the 80-year-old individuals recovered their masticatory ability with the assistance of prostheses. Several individuals with 20 or more remaining teeth or without removable dentures present in both jaws had a high score for bite forces and masticatory abilities.

Gallbladder cancer (GBC) is a particularly deadly type of cancer with a 5-year survival rate of only 10%. New effective therapeutic strategies are greatly needed. Recently, we have shown that Hedgehog (Hh) signaling is reactivated in various types of cancer and is a potential therapeutic target. However, little is known about the biological significance of Hh signaling in human GBC. In this study, we determined whether Hh signaling could be a therapeutic target in GBC. The Hh transcription factor Gli1 was detected in the nucleus of GBC cells but not in the nucleus of normal gallbladder cells. The expression levels of Sonic Hh (Shh) and Smoothened (Smo) in human GBC specimens (n = 37) were higher than those in normal gallbladder tissue. The addition of exogenous Shh ligand augmented the anchor-dependent and anchor-independent proliferation and invasiveness of GBC cells in vitro. In contrast, inhibiting the effector Smo decreased the anchor-dependent and anchor-independent proliferation. Furthermore, the suppression of Smo decreased GBC cell invasiveness through the inhibition of MMP-2 and MMP-9 expression and inhibited the epithelial–mesenchymal transition. In a xenograft model, tumor volume in Smo siRNA-transfected GBC cells was significantly lower than in control tumors. These results suggest that Hh signaling is elevated in GBC and may be involved in the acquisition of malignant phenotypes, and that Hh signaling may be a potential therapeutic target for GBC.