Background CD155 is an immune checkpoint protein that interacts with ligands on natural killer cells to regulate the tumor associated immunity. CD155 overexpression has been detected in many human cancer types. CD155 and its pathways are promising tumor immunotherapy targets. We aimed to evaluate the immunohistochemical expression of CD155 in invasive breast carcinomas and to correlate such expression with the pathological parameters of the tumors and also with natural killer - tumor infiltrating lymphocytes (NK-TILs) density in breast carcinomas tissue as highlighted by CD56 immunostaining. This study included 78 cases of breast carcinomas. Immunohistochemistry was performed using antibodies against CD155 which was detected on the tumor cells and CD56 as a marker for stromal NK cells. Results CD155 expression by the tumor cells was detected in 30.8% of the cases and correlated significantly with advanced prognostic stage, Estrogen receptor (ER) and Progesterone receptor (PR) negativity, high Ki-67 index and Human epidermal receptor 2 (HER2) enriched molecular subtype. High stromal TILs CD56 expression was detected in 28.2% of the cases and correlated significantly with high histologic grade, PR negativity, HER2 neu over-expression, high Ki-67 index, high stromal TILs and more aggressive molecular subtypes; triple negative breast cancer, HER2 enriched and Luminal B-HER2 positive. Finally, statistically significant direct correlation was detected between Tumor cells CD155 expression and high TILs CD56 expression. Conclusions Our results support tumor cell CD155 expression and TILs CD56 expression in breast cancers that are high grade, TILs rich and hormone receptors negative, highlighting those cases as possible candidates for CD155 targeted therapy.

Background Gliomas are the commonest primary adults’ brain tumors. Hypoxia performs an essential role in gliomas’ initiation as well as progression through hypoxia inducible factor (HIF-1α) activation, which could serve as a promising target in treatment of gliomas. Our study aimed to evaluate types and grades of glioma cases and detect isocitrate dehydrogenase 1 (IDH1) mutation status and expression of HIF-1α in all included cases and its correlation with clinical data and pathological parameters. Results Samples from 71 patients who were diagnosed with glioma were studied immunohistochemically for IDH1-R132H (if indicated) and HIF-1α expression. Expression of HIF-1α was detected in 73.2% of the included 71 gliomas. HIF-1α expression significantly increased in older patients, in high-grade gliomas and in tumors positive for necrosis. We studied IDH1 mutation in the histologically diagnosed grade 2, 3and 4 astrocytic and oligodendroglial tumors (51 cases out of the included 71 gliomas). IDH1-R132H immunohistochemical expression was positive in 62.7% of cases. IDH1 mutation was significantly higher with younger age. IDH1 mutation was noted also with lower tumor grade. A statistically significant relation was detected between negative IDH1-R132H expression and high level of HIF-1α immunohistochemical expression. Conclusion Absence of IDH1 mutation with increased HIF-1α expression among high-grade gliomas suggesting both as predicting indicators for poor prognosis.