Enhancement of erbB2 and erbB3 expression during oral oncogenesis in diabetic rats

Cutaneous clear cell/signet-ring cell squamous cell carcinoma arising in the right thigh of a patient with type 2 diabetes: combined morphologic, immunohistochemical, and etiologic analysis

BACKGROUND

The clear cell/signet-ring cell variant of cutaneous squamous cell carcinoma (cSCC) is extremely rare. Its carcinogenesis has consistently been linked to ultraviolet radiation and HPV in the literature. However, there is little definite information about the contribution of diabetes mellitus (DM) to cSCC.

CASE PRESENTATION

A 78-year-old Chinese woman with type 2 DM presented with a mushroom-like lump in her right thigh. Histological findings revealed that the lesion was mainly composed of clear cells and signet-ring cells. The septa of vacuoles in cytoplasm displayed positivity for periodic acid schiff (PAS) and cytokeratins such as AE1/AE3, CK5/6, CK14, and CK19. Malignant cells did not express CK7, CK8, CK18, CK20, p16, p53, or c-erbB-2, and the Ki-67 index was less than 5 %. We further explored the etiology of clear cell/signet-ring cell cSCC using human papillomavirus (HPV) type-specific PCR and genotyping and confirmed that the patient was not infected with HPV. Nucleus positivity for p63 indicated the involvement of the p53 family in the lesion. Meanwhile, the expression of fibroblast growth factor receptor-2 (FGFR2), a downstream effector of p63, was upregulated in tumor cells.

CONCLUSIONS

This study provides the first report on the clear cell/signet-ring cell variant of cSCC found in the right thigh of a patient with type 2 DM. Metabolic imbalance in addition to conventional pathogens such as UV and HPV may contribute to the development of the lesion via p63/FGFR2 axis.

Immunohistochemical Assessment of HER3 Expression in Odontogenic Cysts

Background:

It has been demonstrated that HER3 plays an important role in some human cancers and the HER3 expression is associated with worse survival in solid tumors.

Objectives:

This study was conducted to compare HER3 expression in epithelial lining of radicular cysts (RCs), dentigerous cysts (DCs) and odontogenic keratocysts (OKCs).

Materials and Methods:

This was a descriptive-analytical study, which assessed all 57 paraffin blocks of RCs, DCs and OKCs (21 RCs, 16 DCs, 20 OKC) from pathological archive of Dentistry College of Zahedan, Iran. The HER3 expression in cytoplasm and membrane was examined by immunohistochemical method. The data collected was analyzed using SPSS16 by ANOVA and Chi-square. P < 0.05 was considered as statistically significant.

Results:

The HER3 expression had positive results in 52.4% of OKC, 50% of DC and only 20% of RC samples. There was a significant difference between HER3 expression in OKCs and RCs.

Conclusions:

The HER3 expression in developmental odontogenic cysts was higher than that in inflammatory odontogenic cysts. The higher rate of HER3 expression in OKC may justify inherent growth potential, stimulation-independent proliferation capability, invasive growth and high recurrence rate of the cyst accepted today as a tumor.

The ERBB3 receptor in cancer and cancer gene therapy

ERBB3, a member of the epidermal growth factor receptor (EGFR) family, is unique in that its tyrosine kinase domain is functionally defective. It is activated by neuregulins, by other ERBB and nonERBB receptors as well as by other kinases, and by novel mechanisms. Downstream it interacts prominently with the phosphoinositol 3-kinase/AKT survival/mitogenic pathway, but also with GRB, SHC, SRC, ABL, rasGAP, SYK and the transcription regulator EBP1. There are likely important but poorly understood roles for nuclear localization and for secreted isoforms. Studies of ERBB3 expression in primary cancers and of its mechanistic contributions in cultured cells have implicated it, with varying degrees of certainty, with causation or sustenance of cancers of the breast, ovary, prostate, certain brain cells, retina, melanocytes, colon, pancreas, stomach, oral cavity and lung. Recent results link high ERBB3 activity with escape from therapy targeting other ERBBs in lung and breast cancers. Thus a wide and centrally important role for ERBB3 in cancer is becoming increasingly apparent. Several approaches for targeting ERBB3 in cancers have been tested or proposed. Small inhibitory RNA (siRNA) to ERBB3 or AKT is showing promise as a therapeutic approach to treatment of lung adenocarcinoma.