Biomedical subjects

Hwal Woong Kim

Publications and source records attributed to Hwal Woong Kim.

3 recordsLinked to original sources

PubMed2006

Gene expression in mixed type liposarcoma.

AIMS: Mixed type liposarcomas are rare. Here, we analysed the characteristics of an unusual case of mixed type liposarcoma, which consisted of a well-differentiated liposarcoma (WDL) and a pleomorphic liposarcoma (PL), with a special emphasis on molecular alterations. METHODS: Microscopic and immunohistochemical approaches were used to investigate this case of mixed type liposarcoma, and to identify molecular alterations in this tumour, gene expression was examined in PL, WDL, and normal adipose tissue (NA) samples using a 17,000 cDNA microarray. RESULTS: The tumour mass, 9 x 5 x 5 cm, was located in the left upper arm of a 76-year-old man. Grossly, the proximal portion of the tumour was composed of a yellowish fatty lesion, whereas the distal portion of the tumour was whitish and necrotic in nature. Histologically, the tumour was composed of two distinct components. The proximal component of the tumour was a WDL and the distal component was a PL. Immunohistochemically, S100 protein immunoreactivity highlighted lipoblasts in both tumour portions. The Ki-67 proliferation index was <1% in the WDL and 20% in the PL. MDM2 was positive in the WDL, but negative in the PL. p53 was negative in both areas. Numerous differentially expressed genes were found, which included genes coding for signal transduction, transcription, cell cycle, enzyme, structural protein, immune system and others. CONCLUSIONS: Our data demonstrate that multiple genes are differentially expressed in mixed type liposarcoma and suggest that these genes are associated with the differences in the morphological characteristics and pathogenesis of mixed type liposarcoma.

Adipose Tissue↗

PubMed2004

Heterozygous mice for TGF-betaIIR gene are resistant to the progression of streptozotocin-induced diabetic nephropathy.

BACKGROUND: Transforming growth factor-beta (TGF-beta) receptor complex and its downstream Smad signaling intermediates constitute an extracellular matrix (ECM) accumulation pathway. METHODS: In the present study, we examined whether decreased expression of the TGF-beta type II receptor (TGF-betaIIR) in TGF-betaIIR gene heterozygous (TGF-betaIIR+/-) (HT) mice could inhibit the Smad signaling pathway and subsequent progression of renal lesions when streptozotocin (STZ) diabetes is induced. RESULTS: At the end of the 28-week experiment after STZ injections, wild-type diabetic mice showed severe glomerular hypertrophy and mesangial matrix accumulation occasionally featuring nodular glomerulosclerosis. In contrast, mean glomerular area and mesangial volume density were significantly decreased in the HT diabetic mice as compared with the wild-type diabetic mice. Immunostaining for phosphorylated Smad2/Smad3 and TGF-betaIIR in the glomerular cells was also significantly reduced in the HT diabetic mice. Southwestern histochemistry using digoxigenin-labeled CAGA sequence probes showed that localization of labeled probes to the nuclei of glomerular cells in the HT diabetic mice was significantly less frequent than that in the wild-type diabetic animals. Northern blot analysis showed that alpha1(IV) collagen mRNA levels were significantly reduced in the kidney tissue of HT diabetic mice as compared with the wild-type diabetic mice. CONCLUSION: These results suggest that decreased expression of TGF-betaIIR in the HT diabetic mice can inhibit the progression of diabetic renal injury by inhibiting the downstream Smad signaling pathway and subsequent ECM gene expression. Thus, TGF-betaIIR appears to play an important role in the progression of diabetic nephropathy by mediating intracellular Smad signaling.

Animals↗

PubMedDate not supplied

Fine needle aspiration cytology of epithelioid angiosarcoma. Report of a case with nuclear grooves and indentations.

BACKGROUND: Angiosarcoma, because of its rarity and histologic diversity, has been a persistent challenge to cytopathologists. Epithelioid angiosarcomas are often confused with carcinomas, melanomas and other epithelioid sarcomas, both cytologically and histologically. Here we report the cytopathologic features of a case of epithelioid angiosarcoma with prominent nuclear grooves. CASE: A 61-year-old male visited the hospital with a neck mass. On fine needle aspiration the hypercellular smear, with a lymphocytic bloody background, showed variable-sized, round to oval, pleomorphic cells with frequent nuclear grooves, indentations and plump cytoplasm. The cells were diffusely scattered or loosely aggregated, with occasional acinar and cell-in-cell configuration. The case was diagnosed as epithelioid angiosarcoma on excisional biopsy. CONCLUSION: Whenever fine needle aspiration cytology, especially in the head and neck area, suggests malignancy composed predominantly of epithelioid cells, epithelioid angiosarcoma should be considered. The differential diagnosis should include metastatic tumors, such as carcinoma, melanoma and primary sarcoma. Nuclear grooves and indentations are 1 of the important diagnostic features of epithelioid angiosarcoma.

Biomarkers, Tumor↗