Background: The current study examined the key proteins involved in autophagosome formation and their prognostic role in gastric cancer. Materials and Methods: Paraffin-embedded tissues from 121 consecutive patients treated with surgery for gastric cancer were analyzed immunohistochemically for the expression of autophagic proteins microtubule-associated proteins 1A/1B light chain 3A and 3B (LC3A, LC3B) and beclin-1 (encoded by BECN1 gene). Assessment of proliferative index using E3 ubiquitin-protein ligase (MIB1) and correlations with histopathological parameters and overall survival were performed. Results: Strong cytoplasmic expression was noted for all studied proteins, although to a varying proportion, the median percentage being 30% for LC3A, and 40% for LC3B and beclin-1. The median score of LC3A + stone-like structures (SLS) was 0.2 (range 0-1) and the median proliferative index was 30% (range=0-95%). A significant association between LC3A, LC3B and beclin-1 expression was confirmed (p<0.01). SLS score was higher in tumors of the gastro-esophageal junction (p=0.009), and beclin-1 was overexpressed in intestinal-type tumors (p=0.001). High SLS score (p=0.008) was significantly related to poor prognosis, and this finding persisted in multivariate analysis (hazard ratio(HR)=2.01, p=0.003). Conclusion: Intense autophagic activity, as assessed by LC3A immunostaining and SLS quantification, is a strong prognostic marker in gastric cancer and can be useful for clinical application.

No abstract

Background: Inducible Nitric Oxygen Synthase (iNOS) promotes the generation of NO in tissues. Its role in tumor progression and immune response is unclear. Methods: The immunohistochemical expression patterns of iNOS were studied in a series of 98 tissue samples of non-small-cell lung carcinoma (NSCLC), in parallel with the expression of hypoxia and anaerobic metabolism markers, PD-L1 and tumor-infiltrating lymphocytes (TILs). Results: iNOS is expressed by cancer cells in 19/98 (19.4%), while extensive expression by cancer-associated fibroblasts occurs in 8/98 (8.2%) cases. None of these patterns relate to stage or prognosis. Extensive infiltration of the tumor stroma by iNOS-expressing TILs (iNOS+TILs) occurs in 47/98 (48%) cases. This is related to low Hypoxia-Inducible Factor 1α (HIF1α), high PD-L1 expression and a better overall survival (p = 0.002). Expression of PD-L1, however, mitigates the beneficial effect of the presence of iNOS+TIL. Conclusions: Extensive expression of iNOS by TILs occurs in approximately 50% of NSCLCs, and this is significantly related to an improved overall survival. This brings forward the role of iNOS in anti-neoplastic lymphocyte biology, supporting iNOS+TILs as a putative marker of immune response. The value of this biomarker as a predictive and treatment-guiding tool for tumor immunotherapy demands further investigation.

No abstract

Background/Aim: The role of senescence in defining tumor aggressiveness at a clinical level remains obscure. A novel mixed histochemical/immunohistochemical method (SenTraGor™, STG) detecting lipofuscin accumulation allows the assessment of senescent cells in paraffin-embedded tissue material. Materials and Methods: STG expression was quantified in 98 surgically resected primary non-small-cell-lung carcinomas (NSCLC). Data were analyzed in parallel with other immunohistochemical markers related to hypoxia and autophagy. Results: Strong STG staining was noted in 36/98 cases (36.7%). High STG expression was significantly associated with high HIF1α expression and high expression of glucose (GLUT1) and monocarboxylate (MCT2) transporters, pointing to a link between senescence, hypoxia and glycolysis. High STG expression was also linked with high cytoplasmic accumulation of MAP1-LC3B, TFEB and LAMP2a, suggestive of a blockage of autophagy flux in tumors with intense senescence. Survival analysis showed a direct association with poor survival, independently of stage. Conclusion: SenTraGor™ provides a reliable methodology to detect lipofuscin accumulation in cancer cells in paraffinembedded tissues, opening a new field for translational studies focused on senescence.