ArrayExpress Uploaderarrayexpress_sidhuman68negativeclear444negativeclear1a73negativeundifferentiated3b53negativeclear1c54negativeendometrioid1c54negativeserous2a75negativeserous/clear3c47negativemucinous1c48negativeclear1a45negativeclear1a28negativeserous1a46negativeclear2c60negativeclear3c50negativeendometrioid1c52negativeserous1c53negativemucinous1c61negativeserous3c63negativeserous1a45negativecarcinosarcoma1a57negativeclear1c45negativeserous3c53negativeclear1c57negativeserous3b46negativeendometrioid2c58negativeclear1a61negativeclear2a48negativeendometrioid2c73negativeserous1c74negativeserous3c68negativeclear1a44negativeendometrioid1a52negativeendometrioid1c46negativeendometrioid2c53positiveendometrioid1c35positiveserous3c51positiveserous3c55positiveserous3c44positiveclear3c66positiveserous3c49positiveserous445positiveclear1c58positiveundifferentiated3c47positiveserous3c64positiveendometrioid1c50positiveendometrioid3b55positiveendometrioid3c42positiveserous3c64positiveserous3c54positiveserous2c72positiveserous3c35positiveserous3c49positiveserous3b40positiveserous3c55positiveendometrioid3b48positiveserous3c32positiveclear481positiveserous3c50positiveserous low grade3b65positiveserous456positiveserous3c59positiveserous1c46positiveclear457positiveendometrioid451positiveserous3c452904Ovarian cancer often progresses by disseminating to the peritoneal cavity, but how the tumor cells evade host immunity during this...E-GEOD-39204/profile/8773/arrayexpressuploader464cancercellgenomeimmune systemovarian cancerperitoneal cavityDec.12, 2014Falsegene-expression-profiles-of-ascites-cytology-positE-GEOD-39204_A-AFFY-44Gene-expression profiles of ascites-cytology-positive ovarian cancerSep.19, 2014Ovarian cancer often progresses by disseminating to the peritoneal cavity, but how the tumor cells evade host immunity during this process is poorly understood. Programmed cell death 1 ligand 1 (PD-L1) is known to suppress immune system and to be an unfavorable prognostic factor in ovarian cancer. The purpose of this study was to elucidate the function of PD-L1 in peritoneal dissemination. Positive cytology in ascites was a significant poor prognostic factor in ovarian cancer. Microarray profiles of cytology-positive cases showed significant correlations with Gene Ontology terms related to immune system process. Microarray and immunohistochemistry in human ovarian cancer revealed significant correlation between PD-L1 expression and positive cytology. PD-L1 expression on mouse ovarian cancer cells was induced upon encountering lymphocytes in the course of peritoneal spread in vivo and upon co-culturing with lymphocytes in vitro. Tumor cell lysis by CTLs was attenuated when PD-L1 was overexpressed and promoted when it was silenced. PD-L1 overexpression also inhibited gathering and degranulation of CTLs. In mouse ovarian cancer dissemination models, depleting PD-L1 expression on tumor cells resulted in inhibited tumor growth in the peritoneal cavity and prolonged survival. Restoring immune function by inhibiting immune-suppressive factors such as PD-L1 may be a promising therapeutic strategy for peritoneal dissemination. Genome-wide transcriptional changes in human ovarian cancer tissue from ascites-cytology-positive or -negative patients.http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-39204http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-39204/samples/