Clostridium perfringens enterotoxin induces claudin-4 to activate YAP in oral squamous cell carcinomas

Abstract

Claudin (CLDN)-4 expression has been associated with malignancy in various cancers. When CLDN4 expression was examined in oral squamous cell carcinoma (OSCC), 22 out of 57 (39%) cases showed immunoreactivity in the nucleus. Nuclear CLDN4-positive cases showed a stronger correlation with cancer progression than the negative cases. Intratumoral anaerobic bacterial DNA examination revealed nuclear CLDN4 expression in 81% of Clostridium perfringens-positive cases. Treatment of human oral squamous cell carcinoma cell lines HSC3 and HSC4 with Clostridium perfringens enterotoxin (CPE), induced CLDN4 nuclear translocation to enhance epithelial-mesenchymal transition (EMT), stemness, cell proliferation and invasive ability. In addition, CPE treatment suppressed phosphorylation of yes-associated protein-1 (YAP1) and promoted YAP1 nuclear translocation, resulting in increased expression of YAP1 target genes; cyclin D1 and connective tissue growth factor. Moreover, it was revealed that the complex of YAP1, CLDN4 and zona occludens-2 (ZO-2) was formed by CPE treatment, further suppressing YAP1 phosphorylation by LATS1 and activating it. Thus YAP activation in OSCC was regarded important in promoting malignant phenotypes. Our research suggested that the control of oral anaerobic bacteria may suppress YAP activation and in turn tumor progression.

Effect of Proton Pump Inhibitors on Colorectal Cancer

“…In our analysis of CRC patients, CPE was also detected in patients receiving long-term administration of PPI. We previously reported that CPE produced by C. perfringens impairs CLDN4, which forms tight junctions, to promote cancer progression by activating YAP [19]. Consistent with this, in the present study, CPE activated YAP to enhance the expression of cyclin D1 and NS, which are target genes of YAP.…”

“…Bacterial DNA detection by PCR was performed as previously described [19]. Bacterial DNA was extracted from the CRC specimens (10 thin-sliced paraffin-embedded tumor specimens, deparaffinized and hydrated) using the QIAamp DNA mini kit (Qiagen, GmbH, Hilden, Germany) according to the manufacturer's instructions.…”

“…PPIs also exacerbated C. perfringens enteritis in a mouse model [18]. Recently, we reported that C. perfringens enterotoxin (CPE) enhances cancer malignancy by impairing tight junctions [19].…”

Role of Clostridium perfringens Enterotoxin on YAP Activation in Colonic Sessile Serrated Adenoma/Polyps with Dysplasia

“…Non-membranous CLDN4 localization is reported to be mediated by CPE [18]. Therefore, we examined CPE gene expression in the adenoma tissues ( Figure 3A).…”

“…High concentration of c-terminus of CPE binds to second extracellular loop of CLDN4 to destruct homotipic claudin bindings of the tight junction to provide diarrhea [16]. In contrast, we have reported that impairment of tight junction by low concentration of CPE leads to activation of YAP by internalization of CLDN4 in oral squamous cell carcinoma (OSCC) [18]. In the present study, we investigated whether such CPE-mediated activation of YAP is involved in the malignant progression of SSA/P and malignant phenotype of CRC, which findings might be expected to provide prevention of CRC.…”