Heterochronic triple primary malignancies with Epstein-Barr virus infection and tumor protein 53 gene mutation:A case report and review of literature

BACKGROUND The diagnosis and etiology of multiple primary malignant neoplasms(MPMNs)are difficult to establish.Here,we report a case of heterochronic triple primary malignancies with gastric cancer,nasopharyngeal squamous cell cancer,and then rectal cancer.CASE SUMMARY The patient was first diagnosed with gastric cancer at the age of 33 in 2014 and underwent distal gastrectomy and gastrojejunostomy and six cycles of adjuvant chemotherapy.Three years later,he was diagnosed with nasopharyngeal cancer and treated with radical chemoradiotherapy in 2017.Recently,a mass in the middle of the rectum was resected and reported as ulcerative,moderately to poorly differentiated adenocarcinoma.Research on the etiology of MPMNs showed that Epstein-Barr virus(EBV)infection may be the cause of gastric cancer and nasopharyngeal squamous cell cancer since these two primary lesions were positive for transcripts of EBV-encoded ribonucleic acid using an in situ hybridization EBV-encoded ribonucleic acid probe in formalin-fixed,paraffinembedded tissue.The cause of rectal cancer may be due to a somatic mutation of tumor protein 53 gene in exon 8(c.844C>T,p.Arg282Trp)through highthroughput sequencing for the rectal cancer.Appropriate standard therapy for each primary cancer was administered,and the patient has no evidence of cancer disease to date.CONCLUSION To our knowledge,this is the first report on heterochronic triple primary malignancies whose cause may be associated with EBV infection and tumor protein 53 genetic mutations.The etiological research may not only elucidate the cause of MPMN but also has implications in clinical management.

Low level of ARID1A contributes to adaptive immune resistance and sensitizes triple-negative breast cancer to immune checkpoint inhibitors

Background Immune checkpoint inhibitors(ICIs)shed new light on triple-negative breast cancer(TNBC),but only a minority of patients demonstrate response.Therefore,adaptive immune resistance(AIR)needs to be further defined to guide the development of ICI regimens.Methods Databases,including The Cancer Genome Atlas,Gene Ontology Resource,University of California Santa Cruz Genome Browser,and Pubmed,were used to screen epigenetic modulators,regulators for CD8+T cells,and transcriptional regulators of programmed cell death-ligand 1(PD-L1).Human peripheral blood mononuclear cell(Hu-PBMC)reconstruction mice were adopted for xenograft transplantation.Tumor specimens from a TNBC cohort and the clinical trial CTR20191353 were retrospectively analyzed.RNA-sequencing,Western blotting,qPCR and immunohistochemistry were used to assess gene expression.Coculture assays were performed to evaluate the regulation of TNBC cells on T cells.Chromatin immunoprecipitation and transposase-accessible chromatin sequencing were used to determine chromatin-binding and accessibility.Results The epigenetic modulator AT-rich interaction domain 1A(ARID1A)gene demonstrated the highest expression association with AIR relative to other epigenetic modulators in TNBC patients.Low ARID1A expression in TNBC,causing an immunosuppressive microenvironment,promoted AIR and inhibited CD8+T cell infiltration and activity through upregulating PD-L1.However,ARID1A did not directly regulate PD-L1 expression.We found that ARID1A directly bound the promoter of nucleophosmin 1(NPM1)and that low ARID1A expression increased NPM1 chromatin accessibility as well as gene expression,further activating PD-L1 transcription.In Hu-PBMC mice,atezolizumab demonstrated the potential to reverse ARID1A deficiency-induced AIR in TNBC by reducing tumor malignancy and activating anti-tumor immunity.In CTR20191353,ARID1A-low patients derived more benefit from pucotenlimab compared to ARID1A-high patients.Conclusions In AIR epigenetics,low ARID1A expression in TNBC contributed to AIR via the ARID1A/NPM1/PD-L1 axis,leading to poor outcome but sensitivity to ICI treatment.