Tumor budding as a potential histopathological biomarker in colorectal cancer:Hype or hope?

Colorectal cancer （CRC）, the third most commonly di- agnosed type of cancer in men and women worldwide is recognized as a complex multi-pathway disease, an observation sustained by the fact that histologically identical tumors may have different outcome, including various response to therapy. Therefore, particularly in early and intermediate stage （stages Ⅱ and Ⅲ, respec- tively） CRC, there is a compelling need for biomarkers helpful of selecting patients with aggressive disease that might benefit from adjuvant and targeted therapy. Histopathological examination shows that likely other solid tumors the development and progression of hu- man CRC is not only determined by genetically abnor- mal cells, but also by intricate interactions between malignant cells and the surrounding microenvironment. This has led to reconsider the features of tumor mi- croenvironment as potential predictive and prognostic biomarkers. Among the histopathological biomarkers, tumor budding （i.e., the presence of individual cells and small clusters of tumor cells at the tumor invasive front）has received much recent attention, particularly in the setting of CRC. Although its acceptance as a reportable factor has been held back by a lack of uniformity with respect to qualitative and quantitative aspects, tumor budding is now considered as an independent adverse prognostic factor in CRC that may allow for stratifica- tion of patients into risk categories more meaningful than those defined by tumor-node-metastasis staging alone, and also potentially guide treatment decisions, especially in T2-T3 NO （stage Ⅱ） CRCs.

Prognostic value of innate and adaptive immunity in colorectal cancer

Colorectal cancer(CRC) remains one of the major public health problems throughout the world.Originally depicted as a multi-step dynamical disease,CRC develops slowly over several years and progresses through cytologically distinct benign and malignant states,from single crypt lesions through adenoma,to malignant carcinoma with the potential for invasion and metastasis.Moving from histological observations since a long time,it has been recognized that inflammation and immunity actively participate in the pathogenesis,surveillance and progression of CRC.The advent of immunohistochemical techniques and of animal models has improved our understanding of the immune dynamical system in CRC.It is well known that immune cells have variable behavior controlled by complex interactions in the tumor microenvironment.Advances in immunology and molecular biology have shown that CRC is immunogenic and that host immune responses influence survival.Several lines of evidence support the concept that tumor stromal cells,are not merely a scaffold,but rather they influence growth,survival,and invasiveness of cancer cells,dynamically contributing to the tumor microenvironment,together with immune cells.Different types of immune cells infiltrate CRC,comprising cells of both the innate and adaptive immune system.A relevant issue is to unravel the discrepancy between the inhibitory effects on cancer growth exerted by the local immune response and the promoting effects on cancer proliferation,invasion,and dissemination induced by some types of inflammatory cells.Here,we sought to discuss the role played by innate and adaptive immune system in the local progression and metastasis of CRC,and the prognostic information that we can currently understand and exploit.

Epithelial-to-mesenchymal transition in pancreatic ductal adenocarcinoma: Characterization in a 3D-cell culture model

AIM: To analyze the effect of three-dimensional (3D)-arrangement on the expression of epithelial-to-mesenchymal transition markers in pancreatic adenocarcinoma (PDAC) cells.METHODS: HPAF-II, HPAC, and PL45 PDAC cells were cultured in either 2D-monolayers or 3D-spheroids. Ultrastructure was analyzed by transmission electron microscopy. The expression of E-cadherin, β-catenin, N-cadherin, collagen type I (COL-I), vimentin, α-smooth muscle actin (αSMA), and podoplanin was assayed by confocal microscopy in cells cultured on 12-mm diameter round coverslips and in 3D-spheroids. Gene expression for E-cadherin, Snail, Slug, Twist, Zeb1, and Zeb2 was quantified by real-time PCR. E-cadherin protein level and its electrophoretic pattern were studied by Western blot in cell lysates obtained from cells grown in 2D-monolayers and 3D-spheroids.RESULTS: The E-cadherin/β-catenin complex was expressed in a similar way in plasma membrane cell boundaries in both 2D-monolayers and 3D-spheroids. E-cadherin increased in lysates obtained from 3D-spheroids, while cleavage fragments were more evident in 2D-monolayers. N-cadherin expression was observed in very few PDAC cells grown in 2D-monolayers, but was more evident in 3D-spheroids. Some cells expressing COL-I were observed in 3D-spheroids. Podoplanin, expressed in collectively migrating cells, and αSMA were similarly expressed in both experimental conditions. The concomitant maintenance of the E-cadherin/β-catenin complex at cell boundaries supports the hypothesis of a collective migration for these cells, which is consistent with podoplanin expression.CONCLUSION: We show that a 3D-cell culture model could provide deeper insight into understanding the biology of PDAC and allow for the detection of marked differences in the phenotype of PDAC cells grown in 3D-spheroids.