Ga-Eon Kim

Immunocytochemical panel for distinguishing between adenocarcinomas and reactive mesothelial cells in effusion cell blocks.

The aim of our study was to determine the value of a panel that consisted of one epithelial marker (MOC‐31) and two mesothelial markers (D2‐40 and calretinin) for distinguishing between reactive mesothelial cells (RMCs) and adenocarcinomas (ACs) in effusion fluids. A total of 118 cell block specimens from pleural and peritoneal effusions, including 88 ACs and 30 benign effusions with RMCs were stained with antibodies against MOC‐31, D2‐40, and calretinin. MOC‐31 membranous activity was observed in all samples from ACs, regardless of the primary tumor site. All benign effusion samples with RMCs were negative for MOC‐31. All benign effusion samples with RMCs exhibited membranous staining for D2‐40, and one AC case had focal reactivity for D2‐40. Almost all benign effusions reacted positively with calretinin. Staining was noted in both the cytoplasm and the nucleus in the majority of cases. Scattered tumor cells had weak calretinin positivity in two AC cases. Background RMCs in AC effusions were consistently positive for D2‐40 and calretinin. In general, D2‐40 identified more RMCs than calretinin. The staining combination of positive for MOC‐31 and negative for D2‐40 or calretinin were 100% specific and 99% sensitive for ACs. Our data suggest that immunohistochemical studies performed on cell blocks with MOC‐31, D2‐40, and calretinin were useful in the differentiation between ACs and RMCs. D2‐40 was a more sensitive marker for RMCs than calretinin. Diagn. Cytopathol. 2009.

Stromal matrix metalloproteinase-14 expression correlates with the grade and biological behavior of mammary phyllodes tumors.

Phyllodes tumors (PTs) of the breast are rare biphasic tumors with the potential for invasion and metastatic spread. Matrix metalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs) are involved in several key aspects of tumoral growth, invasion, and metastasis, but little is known of their expression in PTs. The objective of this study was to assess the expression of MMPs and TIMPs in PTs and to determine their association with grade and clinical behavior of PTs. Eighty-two PTs (50 benign, 22 borderline, and 10 malignant) were studied. Automated immunohistochemical staining for MMP-1, -2, -7, -9, -11, -13, and -14 and TIMP-1, -2, and -3 was performed using tissue microarray blocks and the expression of MMPs and TIMPs was assessed in the stromal component. There were no significant differences in the expression of stromal MMPs and TIMPs in the 3 groups of PTs, except for MMP-14. There was a significant increase in stromal MMP-14 expression with increasing PT grade (P<0.01). The stromal MMP-14 expression in the borderline and malignant PTs was higher than that in benign PTs (P<0.05 and P<0.05, respectively). Furthermore, the expression of stromal MMP-14 was associated with a higher rate of recurrence (P<0.05). Our results show for the first time that stromal MMP-14 expression is associated with the grade and clinical behavior of PTs of the breast.

Expression of matrix metalloproteinases and their inhibitors in different immunohistochemical-based molecular subtypes of breast cancer

BackgroundMetalloproteinases (MMPs) and their tissue inhibitors of metalloproteinases (TIMPs) are involved in several key pathways of tumor growth, invasion and metastasis, but little is known about their expression according to different molecular subtypes of breast cancer. The aims of this study were to assess the prevalence and clinical significance of MMP and TIMP expression in invasive breast cancer and to determine its association with immunohistochemical-based molecular classification.MethodsTissue microarray sections were immunostained for estrogen receptor-α (ER-α), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), cytokeratin (CK) 5/6, epidermal growth factor receptor (EGFR) and with specific antibodies against MMP-1, 2, 7, 9, 11, 13, and 14 and TIMP-1, 2, and 3. Based on the immunostaining data from five of the markers used (ER-α, PR, HER2, EGFR and CK5/6), three major subtypes (123 luminal A, 31 basal-like, and 17 HER2-overexpressing) were selected.ResultsStatistically significant differences in the expression of MMPs and TIMPs among the three subtypes were found in tumoral MMP7 (P = 0.005), tumoral MMP-9 (P = 0.000), tumoral MMP-13 (P = 0.016) and stromal MMP-13 (P = 0.016). The incidence of tumoral MMP-9 expression in the HER2-overexpressing subtype was significantly higher than in the luminal A subtype (P = 0.021). Tumoral MMP-9 and stromal MMP-13 expression were significantly higher in the HER2-overexpressing subtype than in the basal-like subtype (P = 0.000 and P = 0.016, respectively). Tumoral MMP-7 expression was significantly higher in the basal-like subtype compared to luminal A (P = 0.007) and HER2-overexpressing subtype (P = 0.004). Tumoral MMP-13 showed a higher expression in the basal-like subtype than in the HER2-overexpressing subtype (P = 0.010). In multivariate analysis, stage and stromal MMP-1 expression were significantly related to overall survival. Stage was of independent prognostic significance for disease-free survival.ConclusionWe found some variations in MMP and TIMP expression among the immunohistochemical-based molecular subtypes of breast carcinomas, suggesting differences in their tumor pathophysiology. Additional studies are needed to determine the mechanisms underlying the differences of MMP and TIMP expression in the molecular subtypes for the development of specific therapeutic targets for breast cancer subtypes.

Detection of Slit2 promoter hypermethylation in tissue and serum samples from breast cancer patients

Promoter hypermethylation has been shown to be a common mechanism for inactivation of tumor suppressor genes in breast cancer. The aim of this study was to investigate the prevalence of Slit2 promoter hypermethylation in both the tumor and serum samples of breast cancer patients with ductal carcinoma in situ (DCIS) or invasive breast carcinoma (IBC). The methylation status of Slit2 was investigated in 210 tissue samples (15 breast with no pathological findings, 26 DCIS, and 169 IBC samples) and 123 corresponding serum samples (15 breast with no pathological findings, 26 DCIS, and 82 IBC samples) using methylation-specific polymerase chain reaction. Immunohistochemical staining for Slit2 was also performed using tissue microarray blocks to determine whether Slit2 promoter hypermethylation correlated with loss of Slit2 expression. Slit2 promoter hypermethylation was not detected in breast tissue and serum samples from patients with no pathological findings. DCIS or IBC showed a statistically higher frequency of Slit2 promoter hypermethylation compared to breast with no pathological findings in both the tissue and serum samples; however, there were no statistically significant differences between DCIS and IBC samples. Similar Slit2 promoter hypermethylation patterns were seen in the tissue samples and corresponding serum specimens (p < 0.001). Slit2 promoter hypermethylation was associated with loss of Slit2 expression. These results suggest that Slit2 promoter hypermethylation appears to be responsible for functionally silencing Slit2 expression. Slit2 promoter hypermethylation may be considered as a possible serum marker for early detection of breast cancer.

SPIN90 depletion and Microtubule Acetylation Mediate Stromal Fibroblast Activation in Breast Cancer Progression

Biomechanical remodeling of stroma by cancer-associated fibroblasts (CAF) in early stages of cancer is critical for cancer progression, and mechanical cues such as extracellular matrix stiffness control cell differentiation and malignant progression. However, the mechanism by which CAF activation occurs in low stiffness stroma in early stages of cancer is unclear. Here, we investigated the molecular mechanism underlying CAF regulation by SPIN90 and microtubule acetylation under conditions of mechanically soft matrices corresponding to normal stromal rigidity. SPIN90 was downregulated in breast cancer stroma but not tumor, and this low stromal expression correlated with decreased survival in breast cancer patients. Spin90 deficiency facilitated recruitment of mDia2 and APC complex to microtubules, resulting in increased microtubule acetylation. This increased acetylation promoted nuclear localization of YAP, which upregulated expression of myofibroblast marker genes on soft matrices. Spin90 depletion enhanced tumor progression, and blockade of microtubule acetylation in CAF significantly inhibited tumor growth in mice. Together, our data demonstrate that loss of SPIN90-mediated microtubule acetylation is a key step in CAF activation in low stiffness stroma. Moreover, correlation among these factors in human breast cancer tissue supports the clinical relevance of SPIN90 and microtubule acetylation in tumor development. Cancer Res; 77(17); 4710-22. ©2017 AACR.

Diagnostic Usefulness of MUC1 and MUC4 for Distinguishing between Metastatic Adenocarcinoma Cells and Reactive Mesothelial Cells in Effusion Cell Blocks

Objective: The aim of our study was to determine the diagnostic value of MUC1 and MUC4 for distinguishing between metastatic adenocarcinoma cells (MAC) and reactive mesothelial cells (RMC) in effusion fluids. Study Design: A total of 237 cell block specimens from pleural and peritoneal effusions, including 196 malignant effusions with MAC and 41 benign effusions with RMC, were stained with antibodies against MUC1 and MUC4. Membranous staining with or without cytoplasmic staining was considered to be positive. Results: MUC1 immunoreactivity was observed in 194 (99.0%) of 196 cases of MAC and in 20 (48.8%) of 41 cases of RMC. MUC4 immunoreactivity was observed in 174 (88.8%) of 196 cases of MAC and in 4 (9.8%) of 41 cases of RMC. For distinguishing MAC from RMC, the MUC1 reactivity was found to be 99.0% sensitive and 51.2% specific with a positive predictive value of 90.7% and a negative predictive value of 91.3%. The sensitivity of MUC4 for MAC was 88.8%, the specificity was 90.2%, the negative predictive value was 62.7%, and the positive predictive value was 97.8%. Conclusion: Our data suggest that MUC4 appears to be a sensitive and specific marker for differentiating between MAC and RMC.

Mesonephric Adenocarcinoma of the Uterine Corpus: A Case Report and Diagnostic Pitfall.

Mesonephric adenocarcinoma is a rare tumor type that is usually found in areas where the Wolffian duct was present during the fetal period. We report a case of mesonephric adenocarcinoma of the uterine corpus in a 66-year-old woman who presented with vaginal bleeding. Pelvic magnetic resonance imaging revealed a 2.7-cm-sized irregular thickening and enhancement of the uterine body. The diagnosis following endometrial curettage biopsy was endometrioid adenocarcinoma, and the patient underwent a total hysterectomy with bilateral salpingo-oophorectomy. The tumor was composed of small tubular and ductal components, and a retiform appearance was also observed in the deeper areas. The tumor cells were immunopositive for cytokeratin, vimentin, CD10 with a luminal staining pattern, PAX2, and PAX8, and immunonegative for estrogen receptor and progesterone receptor, which was consistent with tumor of mesonephric origin. Mesonephric neoplasms reveal relatively low-grade nuclear feature, characteristic immunoprofiles (immunonegative for ER and PR, and immunopositive for CD10, PAX2, PAX8, and GATA3), and unique tumor location (myometrium), whereas Müllerian neoplasms such as endometrial adenocarcinoma show various morphology, immunopositivity for ER and PR, and primarily endometrial location. As described above, an integration of the clinical features, morphologic characteristics, and immunohistochemical profiles is needed to make a diagnosis.

Insulin-Like Growth Factor-II mRNA-Binding Protein 3 Expression in Effusion Cytology: A Marker for Metastatic Adenocarcinoma Cells and a Potential Prognostic Indicator in Gastric Adenocarcinoma

Objective: The aim of our study was to identify the diagnostic value of insulin-like growth factor-II mRNA-binding protein 3 (IMP3) in distinguishing metastatic adenocarcinoma cells (MAC) from reactive mesothelial cells (RMC) in effusions. We also investigated the role of IMP3 as a prognostic indicator for patients with malignant effusion. Study Design: A total of 156 cell block specimens, including 116 malignant effusions with MAC and 40 benign effusions with RMC, were subjected to immunocytochemical staining for IMP3. Results: Immunocytochemical studies showed positive staining for IMP3 in 91 of 116 (78.4%) cases of MAC and in 3 of 40 (7.5%) cases of RMC. With regard to distinguishing MAC from RMC, the IMP3 reactivity was found to be 78.4% sensitive and 92.5% specific with a positive predictive value of 96.8% and a negative predictive value of 59.7%. Diffuse IMP3 expression (>25%) in MAC from patients with gastric adenocarcinoma was associated with shorter survival (p = 0.001). Conclusion: Our data suggest that IMP3 is a helpful marker for differentiating MAC from RMC, and that diffuse IMP3 expression is a poor prognostic indicator in patients with gastric adenocarcinoma and malignant effusion.

Reduced RKIP Expression is Associated With Breast Neoplastic Progression and is Correlated With Poor Outcomes and Aberrant Methylation in Breast Carcinoma.

Raf kinase inhibitor protein’s (RKIP) downregulation can predict poor outcome in patients with various types of malignancy. In this study, we aimed to assess the potential involvement of RKIP in breast carcinogenesis and to evaluate its association with outcome variables and aberrant promoter methylation in breast carcinoma (BC). Tissue microarray sections were immunostained for RKIP in 26 normal breasts, 25 usual ductal hyperplasia, 76 ductal carcinoma in situ, and 198 BC specimens. The methylation status of RKIP was also determined in BC. In addition, the mRNA and protein level of RKIP was analyzed in 8 pairs of BC tissues and surrounding normal tissues by quantitative real-time polymerase chain reaction and Western blot analysis, respectively. RKIP mRNA and protein expression was significantly downregulated in BC tissues compared with the surrounding normal tissues (P<0.05 and P<0.01, respectively). Reduced RKIP expression seemed to increase progressively from normal breast to BC (P<0.001). Reduced RKIP expression was significantly associated with metastatic relapse (P<0.001) and was identified as an independent adverse prognostic indicator for disease-free survival (P=0.003). Reduced RKIP expression in BC was significantly correlated with its aberrant promoter methylation (P<0.05). In conclusion, downregulation of RKIP plays an important role in the breast neoplastic progression and correlates with poor prognosis in patients with BC. Aberrant RKIP methylation is one of the mechanisms that lead to downregulation of RKIP in BC.

A Case of Rosai-Dorfman Disease with Highly Elevated Serum Ferritin

Sinus histiocytosis with massive lymphadenopathy, also known as Rosai-Dorfman disease is a rare disorder characterized by proliferation of distinctive histiocytes within lymph node sinuses and lymphatics, sometimes involving extranodal sites. However, clinical suspicion is difficult and there is also a lack of useful diagnostic markers for this disorder prior to histological confirmation. High elevation of serum ferritin is known to be a useful diagnostic marker for various hematologic diseases, including hemophagocytic lymphohistiocytosis and lymphoma. Here, we report a case of fever of unknown origin that presented along with highly elevated serum ferritin (5,780 ng/mL), and was finally diagnosed as Rosai-Dorfman disease by lymph node biopsy.