Wonkyung Jung

SIRT1 Expression Is Associated with Good Prognosis in Colorectal Cancer

Background Silent mating type information regulation 2 homolog 1 (SIRT1), an NAD+-dependent deacetylase, might act as a tumor promoter by inhibiting p53, but may also as a tumor suppressor by inhibiting several oncogenes such as β-catenin and survivin. Deleted in breast cancer 1 (DBC1) is known as a negative regulator of SIRT1. Methods Immunohistochemical expressions of SIRT1, DBC1, β-catenin, surviving, and p53 were evaluated using 2 mm tumor cores from 349 colorectal cancer patients for tissue microarray. Results Overexpression of SIRT1, DBC1, survivin, and p53 was seen in 235 (67%), 183 (52%), 193 (55%), and 190 (54%) patients, respectively. Altered expression of β-catenin was identified in 246 (70%) patients. On univariate analysis, overexpression of SIRT1 (p=0.029) and altered expression of β-catenin (p=0.008) were significantly associated with longer overall survival. Expression of SIRT1 was significantly related to DBC1 (p=0.001), β-catenin (p=0.001), and survivin (p=0.002), but not with p53. On multivariate analysis, age, tumor stage, differentiation, and expression of SIRT1 were independent prognostic factors significantly associated with overall survival. Conclusions SIRT1 overexpression is a good prognostic factor for colorectal cancer, and SIRT1 may interact with β-catenin and survivin rather than p53.

Plexiform angiomyxoid myofibroblastic tumor of the stomach: report of two cases and review of the literature.

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a recently recognized entity. Because of its rarity, only 22 cases have been reported in the English-language literature and most of these are single case reports. We report two cases of gastric PAMT. The tumor cells were bland and plexiform arranged in a myxoid stroma, which was positive for alcian blue. Immunohistochemically, the tumor cells were positive for smooth muscle actin, but negative for c-kit, CD34, desmin, S-100 protein, epithelial membrane antigen, neurofilament, and protein kinase C-theta. Mutation analyses for exon 9, 11, 13, and 17 of KIT genes and 12, 14, and 18 of the platelet-derived growth factor receptor alpha (PDGFRA) genes were performed and the tumors were wild-type for mutation.

Prognostic Significance of Heat Shock Protein 70 Expression in Early Gastric Carcinoma

Background Overexpression of heat shock protein 70 (HSP70) has been observed in many types of cancer including gastric adenocarcinomas, although the exact role of HSP70 in carcinogenesis remains unclear. Methods The study analyzed a total of 458 radical gastrectomy specimens which were immunohistochemically stained with HSP70, p53, and Ki-67 antibodies. Results The study determined that the expression of HSP70 was significantly increased in early gastric cancer (EGC) compared to advanced gastric cancer (p<0.001). The HSP70 expression was correlated with well-differentiated tumor type, intestinal type of Lauren classification and the lower pT and pN stage. Negative expression of Ki-67 and p53 expression was associated with poor prognosis. The study did not find any correlation between HSP70 and p53 expression. The study determined that HSP70 expression in the EGC subgroup was associated with a poor prognosis (p=0.009), as well as negative Ki-67 expression (p=0.006), but was not associated with p53. Based on multivariate analysis, HSP70 expression (p=0.024), negative expression of Ki-67, invasion depth and lymph node metastasis were determined to be independent prognostic markers. Conclusions HSP70 is expressed in the early stages of gastric adenocarcinoma. In EGC, HSP70 is a poor independent prognostic marker and is correlated with a low proliferation index.

Pigmented Perivascular Epithelioid Cell Tumor (PEComa) of the Kidney: A Case Report and Review of the Literature

Heavily pigmented perivascular epithelioid cell tumors (PEComa) are rare, only eight cases of which have been reported. Unlike typical epithelioid angiomyolipoma, most of these tumors have been encountered in female patients without tuberous sclerosis. The long-term prognosis thereof is undetermined. Cytological similarity and heavy melanin pigment make it difficult for pigmented PEComa to be differentiated from pigmented clear cell renal cell carcinoma or malignant melanoma. The immunoprofile of tumor cells, such as human melanoma black-45 expression, as well as the absence or presence of other melanocytic or epithelial markers, are helpful in determining a differential diagnosis. Here we report a case of heavily pigmented PEComa of the right kidney and review the literature describing this tumor. In this case, the immunoprofile and clinical features corresponded well to those described in the literature. Since the prognosis of such disease has not yet been established, close follow-up of this patient was recommended.

SIRT7, H3K18ac, and ELK4 Immunohistochemical Expression in Hepatocellular Carcinoma.

Background SIRT7 is one of the histone deacetylases and is NAD-dependent. It forms a complex with ETS-like transcription factor 4 (ELK4), which deacetylates H3K18ac and works as a transcriptional suppressor. Overexpression of SIRT7 and deacetylation of H3K18ac have been shown to be associated with aggressive clinical behavior in some cancers, including hepatocellular carcinoma (HCC). The present study investigated the immunohistochemical expression of SIRT7, H3K18ac, and ELK4 in hepatocellular carcinoma. Methods A total of 278 HCC patients were enrolled in this study. Tissue microarray blocks were made from existing paraffin-embedded blocks. Immunohistochemical expressions of SIRT7, H3K18ac and ELK4 were scored and analyzed. Results High SIRT7 (p = .034), high H3K18ac (p = .001), and low ELK4 (p = .021) groups were associated with poor outcomes. Age < 65 years (p = .028), tumor size ≥ 5 cm (p = .001), presence of vascular emboli (p = .003), involvement of surgical margin (p = .001), and high American Joint Committee on Cancer stage (III&V) (p < .001) were correlated with worse prognoses. In multivariate analysis, H3K18ac (p = .001) and ELK4 (p = .015) were the significant independent prognostic factors. Conclusions High SIRT7 expression with poor overall survival implies that deacetylation of H3K18ac contributes to progression of HCC. High H3K18ac expression with poor prognosis is predicted due to a compensation mechanism. In addition, high ELK4 expression with good prognosis suggests another role of ELK4 as a tumor suppressor beyond SIRT7’s helper. In conclusion, we could assume that the H3K18ac deacetylation pathway is influenced by many other factors.

Clinical and genomic landscape of gastric cancer with a mesenchymal phenotype

Gastric cancer is a heterogeneous cancer, making treatment responses difficult to predict. Here we show that we identify two distinct molecular subtypes, mesenchymal phenotype (MP) and epithelial phenotype (EP), by analyzing genomic and proteomic data. Molecularly, MP subtype tumors show high genomic integrity characterized by low mutation rates and microsatellite stability, whereas EP subtype tumors show low genomic integrity. Clinically, the MP subtype is associated with markedly poor survival and resistance to standard chemotherapy, whereas the EP subtype is associated with better survival rates and sensitivity to chemotherapy. Integrative analysis shows that signaling pathways driving epithelial-to-mesenchymal transition and insulin-like growth factor 1 (IGF1)/IGF1 receptor (IGF1R) pathway are highly activated in MP subtype tumors. Importantly, MP subtype cancer cells are more sensitive to inhibition of IGF1/IGF1R pathway than EP subtype. Detailed characterization of these two subtypes could identify novel therapeutic targets and useful biomarkers for prognosis and therapy response.The prognosis and treatment of gastric cancer is complicated by heterogeneity. Here, the authors reveal two molecular subtypes, the mesenchymal subtype associated with poor survival and chemoresistance, and the epithelial phenotype associated with better survival and sensitivity to chemotherapy.

Expression and prognostic significance of programmed death protein 1 and programmed death ligand‐1, and cytotoxic T lymphocyte‐associated molecule‐4 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies and causes of death worldwide. In this study, we assessed the correlation between clinicopathologic factors with programmed cell death protein 1 (PD‐1) and programmed cell death ligand‐1 (PD‐L1), and cytotoxic T lymphocyte‐associated molecule‐4 (CTLA‐4) expressions. Furthermore, we analyzed the prognostic significance of these proteins in a subgroup of patients. We retrospectively evaluated the PD‐1, PD‐L1, and CTLA‐4 expressions in 294 HCC tissue microarray samples using immunohistochemistry. PD‐1 and PD‐L1 expressions were significant related to high CD8+ tumor‐infiltrating lymphocytes (TILs) (r = 0.664, p < 0.001 and r = 0.149, p = 0.012). Only high Edmondson–Steiner grade was statistically related to high PD‐1 expression. High PD‐L1 expression was demonstrated as an independent poor prognostic factor for disease‐free survival in addition to previous known factors, size >5 cm and serum albumin ≤3.5 g/dL in high CD8+ TILs group. We have demonstrated that the combined high expression of PD‐L1 and CD8+ TIL is an important prognostic factor related to the immune checkpoint pathway in HCC and furthermore, there is a possibility that it could be used as a predictor of therapeutic response. Also, this result would be helpful in evaluating the applicable group of PD‐1/PD‐L1 blocking agent for HCC patients.

Genomic Copy Number Signatures Uncovered a Genetically Distinct Group from Adenocarcinoma and Squamous Cell Carcinoma in Non–Small Cell Lung Cancer ☆ ☆☆

Adenocarcinoma (AC) and squamous cell carcinoma (SCC) of non-small cell lung carcinoma (NSCLC) have different clinical presentations, morphologies, treatments, and prognoses. Recent studies suggested that fundamental genetic alterations related to carcinogenesis of each tumor type may be different. In this study, we investigated the genomic alterations of 47 primary NSCLC samples (22 ACs and 25 SCCs) as well as the corresponding normal tissue using array comparative genomic hybridization. Frequent copy number alterations (CNAs), which were identified in more than 68% of all of the cases, were evaluated in each subtype (SCC and AC), and a CNA signature was established. Among these CNAs, 37 genes from the SCCs and 15 genes from the ACs were located in a region of gain, and 4 genes from the SCCs and 13 genes from the ACs were located in a region of loss. The most frequent gain was located on 3q26-29 including the gene TP63 in SCCs and 7q11.23 and 7q36.3 in ACs. Moreover, we identified 3 genetically distinct groups (group I [16 SCC] with CNA signature of SCC; group II [7 SCC + 8 AC], which has a genetically distinctive CNA signature from SCC and AC; and group III [2 SCC + 14 AC] with CNA signature of AC) by gene clustering extracted from CNAs, which are associated with a prognosis. The present study contributed to the molecular characterization of AC and SCC of NSCLC and showed a subtype of tumor that has a unique genetic CNA signature. However, further study about the significance of these 3 distinct groups and their usefulness as a diagnostic marker of identified CNAs is necessary.

Biliary intraepithelial neoplasia: a case with benign biliary stricture.

Intrahepatic and extrahepatic cholangiocarcinomas develops through a multistep carcinogenesis sequence and they are preceded by precursor lesions. Precursors of malignant neoplasm are identified in various organs including uterine cervix, gastrointestinal tract and breast. Identification of these precursor lesions are important in that they need minimal treatment or they are good indicator of disease progression or recurrence. In the intrahepatic and extrahepatic biliary tract, precursor lesions of malignancy are defined as follows; biliary intraepithelial neoplasia (BilIN), intraductal papillary neoplasm, mucinous cystic neoplasm, and adenoma.1 BilIN is characterized by atypical epithelial cells with multi-layering of nuclei and micropapillary projections into the lumen of bile duct.2,3 In contrast to intraductal papillary neoplasm which is characterized by papillary proliferation of epithelial cells with fibrovascular stroma and mucin production, BilIN tend to be a microscopic lesion. Mucinous cystic neoplasm is usually cystic lesions and has distinguishing clinicopathologic findings such as subepithelial stroma resembling ovarian stroma and predominant occurrence in adult female. Adenomas are commonly encountered in extrahepatic bile ducts and divided into tubular, papillary and tubulopapillary on the basis of growth pattern.1