HER3 overexpression and hypomethylation in colorectal adenocarcinoma

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cancer in Malaysia. Despite advanced therapies, many cases of recurrence and resistance have been reported. Aberrant DNA methylation of HER3 has been implicated in carcinogenesis of CRC mainly through the regulation of gene expression. Hence, the objective of this study was to determine the status of HER3 DNA methylation and its effects on gene expression in CRC.

MATERIALS AND METHODS

Fifty-nine of archival formalin-fixed, paraffin-embedded CRC cases with the adjacent normal colon tissues were retrieved. Manual micro-dissection was performed prior to RNA and DNA extraction. HER3 gene expression and DNA methylation status was evaluated by qPCR and methylation-specific PCR (MSP) techniques respectively.

RESULTS

Upregulation of HER3 mRNA was found in CRC tissue compared to its adjacent normal colon tissue (8.04-fold). Of 59 CRC samples, 8.5% were methylated and 91.5% were unmethylated (hypomethylation). In the adjacent normal colon tissues, methylated and unmethylated tissue were observed in 6.8%and 93.2% respectively. DNA methylation of HER3 showed a significant association with tumour differentiation and tumour location.

CONCLUSION

This study showed upregulation and hypomethylation of the HER3 gene in CRC cases. Epigenetic alterations were also found in the adjacent normal colon tissues. Thus, upregulation and hypomethylation of HER3 may play a key role in carcinogenesis of CRC. Hypomethylation of CpG islands might be associated with early steps during carcinogenesis. The findings of this biomarker serve a powerful approach to improve the current diagnostic and therapeutic measures.

Juxtarenal/pararenal Wilms' tumour in a six-year-old Malay girl

We report a six-year-old Malay girl who presented with a right retroperitoneal tumour that measured 7.5 cm in diameter. A wide excision of the lesion was performed. The tumour was separated from a normal-appearing right kidney by a capsule. Microscopically, this well-encapsulated tumour was composed of classical triphasic components: epithelial, mesenchymal and blastemal areas. The immunohistochemical study showed WT1 expression in the blastemal area. Thus, a diagnosis of Wilms' tumour with favourable histology was made. The patient was well for 12 months. Extrarenal Wilms' tumour is uncommon, with the majority of cases occurring in the retroperitoneal and inguinal areas. Wilms' tumour that is not arising from the intrarenal area but shares a common capsule with the ipsilateral kidney, is even rarer. Indeed, our case would be more appropriately classified as juxtarenal/pararenal Wilms' tumour. Despite its rarity, an extrarenal or even juxtarenal/pararenal Wilms' tumour should be included in the differential diagnosis of retroperitoneal tumour.

Matrix metalloproteinases (MMP-8, MMP-9) and the tissue inhibitors of metalloproteinases (TIMP-1, TIMP-2) in patients with fungal keratitis

PURPOSE

To study the infiltrating cells and quantify the levels of matrix metalloproteinases (MMP-8, MMP-9) and tissue inhibitor of metalloproteinases (TIMP-1, TIMP-2) in the cornea, tear, and serum of patients with fungal keratitis.

METHODS

Experimental study. Infected corneal tissue from 4 patients with fungal keratitis (group 1) scheduled to undergo therapeutic keratoplasty accounted for the histopathologic and cytospin smear analysis. Ten patients with fungal keratitis from group 2 served for the quantification of MMPs and TIMPs. Five patients with keratoconus undergoing penetrating keratoplasty and 5 cadaver corneas were chosen as controls for group 2. Corneal buttons obtained during keratoplasty, 15 to 20 microL of tears collected using the capillary flow method, and 3 mL of blood was obtained from patients with fungal keratitis and patients with keratoconus. Corneal button sections from group 1 were stained with hematoxylin and eosin and Grocott methenamine silver nitrate for the histopathologic studies and Giemsa staining for the cytospin smear analysis. Enzyme-linked immunosorbent assay was used for the quantification of total MMP-8, MMP-9, TIMP-1, and TIMP-2 in the corneal homogenates, tear, and serum samples of group 2.

RESULTS

Corneal sections from group 1 revealed dense fungal filaments and a large proportion (91.4% +/- 38%) of polymorphonuclear leukocytes (PMNs). Significant elevation in the levels of MMP-8 and MMP-9 (P < 0.05) in the fungal keratitis corneas was observed in group 2 compared with the cadaver and keratoconus corneas. The ratio of MMP/TIMP was also higher in the fungal keratitis corneas.

CONCLUSIONS

Infiltrating PMNs in the cornea of patients with fungal keratitis contributed to the increased activities of MMP-8 and MMP-9, thereby enhancing tissue destruction and derangement.

Aortic dissection in a young patient without any predisposing factors

Aortic dissection is rare in the pediatric and young adult population. We hereby present a case of a 17-year- old male patient, without any predisposing factors, who developed an aortic dissection. The initial presentation was acute abdominal pain with massive retroperitoneal hematoma. His clinical condition deteriorated rapidly, did not respond to surgical hemostasis, and died within 36 hours of admission. The major autopsy finding was dissection of the descending aorta, extending from 2 cm distal from the origin of the left Subclavian artery. Microscopically, the aortic sections showed intimal thickening and tearing, medial smooth muscle loss, which was replaced by fibrous tissue, fragmentation of elastic lamellae with widening of interlamellar spaces, and cystic medial degeneration. The morphological features represented degenerative changes of the aorta, which were unusual in such a young patient. The pathophysiology, predisposing factors and relevant reports in the literature of aortic dissection in young patients are reviewed.

Simultaneous occurrence of Hodgkin's lymphoma and Kaposi's sarcoma within the same lymph nodes of a non-AIDS patient

We report a case of simultaneous occurrence of Hodgkin's lymphoma and Kaposi's sarcoma within the same lymph nodes of a 61-year-old woman without human immunodeficiency virus (HIV) infection. Epstein-Barr virus (EBV) was detected in the Hodgkin cells and Reed-Sternberg cells by EBV LMP-1 immunostaining and Epstein-Barr virus encoded early RNA (EBER) in situ hybridization. In contrast, Kaposi's sarcoma cells were positive for human herpes virus 8. This case is documented because the occurrence of 2 independent tumors infected by 2 unrelated viruses within the same lymph nodes of a patient without HIV infection has rarely been observed.

Clinical and endoscopic features for alimentary tract cytomegalovirus disease: report of 20 cases with gastrointestinal cytomegalovirus disease

BACKGROUND

The clinical presentations and endoscopic features of cytomegalovirus (CMV) infection in the gastrointestinal (GI) tract are diverse, and can mimic other inflammatory gastrointestinal diseases.

METHODS

From 1987 to 2003 at Chang-Gung Medical Center, 20 patients with CMV infections of the GI tract who were assessed using endoscopic examinations and diagnosed via pathologic studies were retrospectively reviewed.

RESULTS

Most of the patients were adults with immunocompromised conditions (10/20). GI tract bleeding was the most common clinical manifestation (11/20). Five patients presented with abdominal pain, and two patients presented with diarrhea. Fifteen patients suffered from fever. The endoscopic abnormalities could be classified into four main groups: inflammatory mucosa alone (3/20), ulceration alone (7/20), inflammatory mucosa associated with ulcer (9/20) and sub-mucosal tumor with ulcer (1/20). Of the 17 patients with ulcer lesions, ten had multiple ulcers and 12 had large ulcers exceeding 2 centimeters in diameter. Of the six patients followed up with colonoscopy, one was free of disease, one had a single ulcer, and four had colitis and were CMV positive on repeat biopsy. Two patients had colon strictures with persistent CMV colitis.

CONCLUSION

Many patients with GI tract CMV infection are immunocompromised. Gastrointestinal bleeding is the most common initial presentation of gastrointestinal CMV disease. Fever is the most common associated toxic sign. Sigmoidoscopy cannot replace colonoscopy for detecting CMV colitis. The most common feature is multiple ulcers with at least one large ulcer. Endoscopic follow-up in patients with CMV colitis is recommended to investigate for possible persistent colitis and strictures.

Solid variant of papillary renal cell carcinoma

Solid variant of papillary renal cell carcinoma is a newly recognized renal epithelial neoplasm. We encounter a case of a 36-year-old male patient with a solitary right renal tumor. The tumor is composed of solid sheets of small uniform cell with intervening micronodules, resembling the glomeruloid bodies in a metanephric adenoma. Abortive papillae rather than typical papillary formations are found in the micronodules. Furthermore, the cells in these micronodules demonstrate more cellular atypia with abundant eosinophilic cytoplasm comparing to the intervening cells. Both types of neoplastic cells are immunoreactive for epithelial membrane antigen, cytokeratins 7 and 17, but not vimentin and 34 beta E12. The features of the tumor are consistent with solid variant of papillary renal cell carcinoma. Solid variant of papillary renal cell carcinoma is similar in certain morphological and genetic features to metanephric adenoma, suggesting that they might be related.

Search for immunomodulatory effects of blood transfusion in gastric cancer patients: flow cytometry of Th1/Th2 cells in peripheral blood

Allogeneic transfusion seems to drive the immune system toward a Th2 response and away from a Th1 response, providing a hypothetical mechanism for transfusion-induced immunomodulation. By means of an intracytoplasmic cytokine detection technique with flow cytometry, it is possible to measure Th1 and Th2 cells derived from peripheral blood mononuclear cells. This study evaluated the presence of transfusion-induced immunomodulation in 11 gastric cancer patients after gastrectomy with perioperative blood transfusion, compared to 11 gastric cancer patients who were treated by gastrectomy without transfusion. Lymphocytes subsets, including CD4 T cells, CD8 T cells, CD4/CD8 Ratio, CD2(+) T cells, CD3(+) T cells, and CD19(+) B cells, were measured in these patients, as well as variables that might suggest transfusion-induced immunomodulation, such as duration of antibiotic use, duration of hospital stay, and total hospital charges. This study also measured changes in the Th1/Th2 ratio. Th1 and Th2 lymphocytes were characterized by measuring intracellular expression of cytokines with flow cytometry. Cells were stimulated with phorbol myristate acetate and ionomycin in the presence of brefeldin-A. The results showed no significant differences in lymphocyte subsets, Th1/Th2 ratio, total hospital charges, or duration of antibiotic utilization between the groups of transfused and non-transfused gastric cancer patients after gastrectomy. The only significant difference was a longer hospital stay for transfused patients (mean 20.5 da) compared to non-transfused patients (mean 16.2 da). The anticipated finding of a Th2 response after blood transfusion was not observed. A larger group of patients may be needed to document such an effect, since many confounding variables affect the morbidity and outcome of surgery in these patients.