ITIH5 induces a shift in TGF‐β superfamily signaling involving Endoglin and reduces risk for breast cancer metastasis and tumor death

Abstract

ITIH5 has been proposed being a novel tumor suppressor in various tumor entities including breast cancer. Recently, ITIH5 was furthermore identified as metastasis suppressor gene in pancreatic carcinoma. In this study we aimed to specify the impact of ITIH5 on metastasis in breast cancer. Therefore, DNA methylation of ITIH5 promoter regions was assessed in breast cancer metastases using the TCGA portal and methylation-specific PCR (MSP). We reveal that the ITIH5 upstream promoter region is particularly responsible for ITIH5 gene inactivation predicting shorter survival of patients. Notably, methylation of this upstream ITIH5 promoter region was associated with disease progression, for example, abundantly found in distant metastases. In vitro, stably ITIH5-overexpressing MDA-MB-231 breast cancer clones were used to analyze cell invasion and to identify novel ITIH5-downstream targets. Indeed, ITIH5 re-expression suppresses invasive growth of MDA-MB-231 breast cancer cells while modulating expression of genes involved in metastasis including Endoglin (ENG), an accessory TGF-β receptor, which was furthermore co-expressed with ITIH5 in primary breast tumors. By performing in vitro stimulation of TGF-β signaling using TGF-β1 and BMP-2 we show that ITIH5 triggered a TGF-β superfamily signaling switch contributing to downregulation of targets like Id1, known to endorse metastasis. Moreover, ITIH5 predicts longer overall survival (OS) only in those breast tumors that feature high ENG expression or inversely regulated ID1 suggesting a clinical and functional impact of an ITIH5-ENG axis for breast cancer progression. Hence, we provide evidence that ITIH5 may represent a novel modulator of TGF-β superfamily signaling involved in suppressing breast cancer metastasis.

ITIH5 and ECRG4 DNA Methylation Biomarker Test (EI-BLA) for Urine-Based Non-Invasive Detection of Bladder Cancer

“…In 2008, ITIH5 was described to be epigenetically silenced in breast cancer [17] and five years later ITIH5 DNA methylation has been identified as a putative blood-based biomarker for the early detection of breast cancer [38]. Since then functionally studies revealed, for instance, ITIH5 mediated suppression of breast [21,22] and pancreatic cancer metastases [23] in vitro and in vivo. Interestingly, in aggressive mammary cancer cells, ITIH5 triggered an epigenetic reprogramming which was associated with a demethylation of various promoter regions, including that of DAPK1, a tumor suppressor gene and putative blood-based biomarker in several tumor entities [21].…”

“…ITIH5 has previously been shown to be epigenetically silenced in various cancer entities [17][18][19], including bladder cancer [20], where its expression was associated with tumor recurrence of the clinical important group of high-grade pT1 patients. In addition, ITIH5 was characterized as a putative metastasis suppressor gene in breast [21,22] and pancreatic cancers [23]. ECRG4 has also been described to be a candidate tumor suppressor gene that is inactivated by DNA methylation in cancers, like esophageal squamous cell carcinoma [24,25], breast cancer [26], renal cell cancer [27], and colorectal cancer [28,29], but not in bladder cancer so far.…”

The Inter-α-Trypsin Inhibitor Family: Versatile Molecules in Biology and Pathology

“…25 Specifically, the HC5 gene has been identified as a tumor suppressor gene in multiple types of cancer, including breast, bladder, pancreatic, and colon cancer and acute myeloid leukemia. 206–210 It can suppress the proliferation and migration of breast, bladder, and colon cancer cells in vitro. 206,207,210 HC5 gene expression is reduced in cancer due to the aberrant hypermethylation of the promoter.…”

“…206–210 It can suppress the proliferation and migration of breast, bladder, and colon cancer cells in vitro. 206,207,210 HC5 gene expression is reduced in cancer due to the aberrant hypermethylation of the promoter. 208,211 Expression of the HC5 gene predicts longer overall survival in gastric and breast cancer and lung adenocarcinoma.…”

“…208,211 Expression of the HC5 gene predicts longer overall survival in gastric and breast cancer and lung adenocarcinoma. 210,212,213 Bikunin has known roles in tumor suppression by inhibiting cell–cell interactions, cell invasion, and metastasis, as well as providing serine proteinase inhibitory activity. 107,117,118,214–219 In support of these findings, bikunin knockout mice have an increased prevalence of lung metastasis.…”