Oncofetal Protein IMP3, a New Cancer Biomarker

Abstract

IMP3 is a member of a family of RNA-binding proteins that consists of IMP1, IMP2 and IMP3. These proteins contain 2 RNA recognition motifs and 4 K-homology domains that allow them to bind RNAs strongly and specifically. IMP3 is an oncofetal protein involved in embryogenesis and its expression is associated with a number of malignant neoplasms. IMP3 is associated with aggressive and advanced cancers and is specifically expressed in malignant tumors but is not found in adjacent benign tissues. Moreover, in vitro studies have shown that IMP3 promotes tumor cell proliferation, adhesion, and invasion. This review focuses on the studies of IMP3 expression in different cancers and emphasizes the potential utility of IMP3 in routine surgical pathology practice. We also discuss IMP3 as a prognostic biomarker for cancer patients' outcomes.

Prognostic significance of insulin-like growth factor-II mRNA-binding protein 3 in urological cancers: a systemic review and meta-analysis

“…Initially, IMP3 was found to be overexpressed in pancreatic cancer tissue as compared with both normal pancreas and chronic pancreatitis tissue [6]. Since then, aberrant IMP3 expression has been detected in multitude of other human malignancies, including lung cancers, hepatobiliary cancers, gastrointestinal cancers, genitourinary cancers, melanoma and thyroid cancers [7]. What's more, these observations…”

“…Recently, IMP3 is reported to be highly expressed in various types of cancer but is not expressed in adjacent benign tissues, and it is associated with tumor aggressiveness as well as poor prognosis [7,21]. As far as we know, IMP3 can promote cell proliferation and promote cell survival by inhibiting translation of insulin-like growth factor II (IGF-II) mRNA, eg.…”

IMP3 Immunoreactivity is More Sensitive Than AMACR in Detecting Dysplastic Epithelium and Early Adenocarcinoma in Barrett Esophagus

“…9,10 IMP3 members play a role in RNA trafficking and stabilization, cell growth, and cell migration during the early stages of embryogenesis. 10 The IMP3 gene is located on chromosome 7 and is identical to the KOC (the KH domain-containing protein overexpressed in cancer) protein that was originally cloned from a pancreatic tumor cDNA screen by Mueller et al 9 in 1997. In previous studies evaluating IMP3 expression in the metaplasia-dysplasia-adenocarcinoma sequence, Lu et al 17 found 7% BE, 14% LGD, 94% HGD, and 93% adenocarcinoma (ACA) expressing IMP3, respectively, and none of the cases with benign esophageal mucosa was positive.…”

“…Clinical studies also demonstrate that aberrant IMP3 expression in tumor cells is associated with aggressive tumoral behavior in renal cell carcinoma, urothelial carcinoma, gastric carcinoma, endometrial carcinoma, and epithelial dysplastic-neoplastic lesions in BE. 10 A review of the literature shows that no immunohistochemical studies have been performed to evaluate the expression of AMACR and IMP3 in the same population in the metaplasia-dysplasia-early adenocarcinoma (EAC) sequence. The aim of our study was to evaluate the expression of IMP3 and AMACR in this setting and compare their relative sensitivity and specificity in identifying difficult cases of dysplastic and early neoplastic epithelium in BE.…”

“…IMP3 is normally expressed in the developing epithelium, the muscle, and the placenta during early stages of human and mouse embryogenesis, but is expressed at low or undetectable levels in adult tissues. 9,10 The overexpression of IMP3 is found in many malignant tumors including pancreas, 11 lung, 12 colon cancer, 13 endometrial serous carcinoma, 14 endocervical adenocarcinoma, 15 and soft tissue sarcomas, 16 but not in adjacent benign tissues. Clinical studies also demonstrate that aberrant IMP3 expression in tumor cells is associated with aggressive tumoral behavior in renal cell carcinoma, urothelial carcinoma, gastric carcinoma, endometrial carcinoma, and epithelial dysplastic-neoplastic lesions in BE.…”