Ovarian cancer: insights into genetics and pathogeny

Starting from the information on ovarian cancer provided by the mainstream publications, we construct a review focusing on the following issues: (i) the genetic profile, (ii) the role of the epithelial-mesenchymal transition in the acquirement of malignant features, (iii) the controversial hypothesis regarding the origin, and (iv) the involvement of the immune system in the tumoral microenvironment. Advances in the decipherment at the genetic level in the pathogenic mechanisms progressively lead to the idea of a genetic signature for the ovarian cancer. Moreover, the complementary approaches oriented towards the decryption of the intrinsic structure of the expressed molecules and, implicitly, the development of proteomics open new perspectives for an early diagnosis and an appropriate treatment. The research on the epithelial-mesenchymal transition (mainly those exploring the signaling pathways responsible for the switch between the loss of the epithelial characteristics and the gain of a mesenchymal cell phenotype, with results in the amplification of differentiation, motility and tumoral invasion) allow a deeper understanding of the complex pathogenic mechanism which governs ovarian carcinogenesis. The classic conception of ovarian cancer pathogeny, based on the role of the ovarian surface epithelium, is currently reconsidered, and a novel hypothesis is formulated, which supports direct involvement of the Fallopian tubes for the serous type. Although recent research suggests the implication of immune/inflammatory cells by specific mechanisms in ovarian cancer pathogenesis, there is yet reliable evidence concerning their modality of direct action and/or modulation of tumoral growth. Thus, ovarian carcinogenesis remains a research challenge, due to still numerous unknown factors involved in the malignant transformation sequences, originating from the genetic-molecular alterations and reflected by cellular and tissue expression patterns

E-Cadherin Modulation and Inter-Cellular Trafficking in Tubular Gastric Adenocarcinoma: A High-Resolution Microscopy Pilot Study

Despite the numerous advances in tumor molecular biology and chemotherapy options, gastric adenocarcinoma is still the most frequent form of gastric cancer. One of the core proteins that regulates inter-cellular adhesion, E-cadherin plays important roles in tumorigenesis as well as in tumor progression; however, the exact expression changes and modulation that occur in gastric cancer are not yet fully understood. In an attempt to estimate if the synthesis/degradation balance matches the final membrane expression of this adhesion molecule in cancer tissue, we assessed the proportion of E-cadherin that is found in the Golgi vesicles as well as in the lysosomal pathway We utilized archived tissue fragments from 18 patients with well and poorly differentiated intestinal types of gastric cancer and 5 samples of normal gastric mucosa, by using high-magnification multispectral microscopy and high-resolution fluorescence deconvolution microscopy. Our data showed that E-cadherin is not only expressed in the membrane, but also in the cytoplasm of normal and tumor gastric epithelia. E-cadherin colocalization with the Golgian vesicles seemed to be increasing with less differentiated tumors, while co-localization with the lysosomal system decreased in tumor tissue; however, the membrane expression of the adhesion molecule clearly dropped from well to poorly differentiated tumors. Thus E-cadherin seems to be more abundantly synthetized than eliminated via lysosomes/exosomes in less differentiated tumors, suggesting that post-translational modifications, such as cleavage, conformational inactivation, or exocytosis, are responsible for the net drop of E-cadherin at the level of the membrane in more anaplastic tumors. This behavior is in perfect accordance with the concept of partial epithelial-to-mesenchymal transition (P-EMT), when the E-cadherin expression of tumor cells is in fact not downregulated but redistributed away from the membrane in recycling vesicles. Moreover, our high-resolution deconvolution microscopy study showed for the first time, at the tissue level, the presence of Lysosome-associated membrane glycoprotein 1 (LAMP1)-positive exosomes/multivesicular bodies being trafficked across the membranes of tumor epithelial cells. Altogether, a myriad of putative modulatory pathways is available as a treatment turning point, even if we are to only consider the metabolism of membrane E-cadherin regulation. Future super-resolution microscopy studies are needed to clarify the extent of lysosome/exosome exchange between tumor cells and with the surrounding stroma, in histopathology samples or even in vivo

Gastric Cancer Angiogenesis Assessment by Dynamic Contrast Harmonic Imaging Endoscopic Ultrasound (CHI-EUS) and Immunohistochemical Analysis—A Feasibility Study

Tumor vascular perfusion pattern in gastric cancer (GC) may be an important prognostic factor with therapeutic implications. Non-invasive methods such as dynamic contrast harmonic imaging endoscopic ultrasound (CHI-EUS) may provide details about tumor perfusion and could also lay out another perspective for angiogenesis assessment. Methods: We included 34 patients with GC, adenocarcinoma, with CHI-EUS examinations that were performed before any treatment decision. We analyzed eighty video sequences with a dedicated software for quantitative analysis of the vascular patterns of specific regions of interest (ROI). As a result, time-intensity curve (TIC) along with other derived parameters were automatically generated: peak enhancement (PE), rise time (RT), time to peak (TTP), wash-in perfusion index (WiPI), ROI area, and others. We performed CD105 and CD31 immunostaining to calculate the vascular diameter (vd) and the microvascular density (MVD), and the results were compared with CHI-EUS parameters. Results: High statistical correlations (p < 0.05) were observed between TIC analysis parameters MVD and vd CD31. Strong correlations were also found between tumor grade and 7 CHI-EUS parameters, p < 0.005. Conclusions: GC angiogenesis assessment by CHI-EUS is feasible and may be considered for future studies based on TIC analysis