Immunocytochemical staining of p16(ink4a) protein as an adjunct test in equivocal liquid-based cytology.

For cervical cancer screening, HPV-DNA test is expensive and is not easily available in all clinical situations. Thus, we investigated the role of p16(ink4a) immunostaining as another adjunct test to diagnose cervical neoplasia in equivocal liquid based cytology. Eighty-seven patients were randomly selected for this study (3 patients with normal, 84 patients with abnormal including 24 ASCUS, 30 LSIL, and 30 HSIL). We performed p16(ink4a) immunostaining on ThinPrep slide and on each case from the corresponding cervical biopsy tissues. High-risk HPV-DNA testing was also performed on all the subjects. We found that the immunoreactivity of p16(ink4a) is strongly correlated with the grade of cytologic and histologic diagnoses as well as with Hybrid Capture 2. In comparing the p16(ink4a) immunostaining with the Hybrid Capture 2 for accuracy of the diagnosis of CIN II/III or a higher-grade disease in the case of ASCUS/LSIL on ThinPrep, no significant differences were observed. Our data implies that p16(ink4a) immunocytochemical staining in liquid-based cytology specimens might be used as a good adjunct test to predict cervical histology in equivocal ThinPrep tests.

Loss of hMLH1 expression is associated with less aggressive clinicopathological features in sporadic endometrioid endometrial adenocarcinoma.

AIM: To assess the incidence and clinicopathological significance of microsatellite instability (MSI) and the protein expression of hMLH1 and hMSH2 in sporadic endometrioid endometrial adenocarcinoma (SEEA). METHODS: A total of 50 patients with pure endometrioid sporadic endometrial adenocarcinoma were enrolled in the study. MSI analysis was done using five polymorphic markers (BAT26, D5S346, BAT25, D17S250, D2S123) and the protein expression of the hMLH1 and hMSH2 genes was determined by immunohistochemical staining. MSI was detected in 24% (12/50) of SEEA cases. RESULTS: There was a significant correlation between MSI status and loss of hMLH1, hMSH2 expression, respectively. No significant association was found between MSI status and clinicopathological parameters, including age, grade, stage, depth of myometrial invasion, lymph-vascular space invasion (LVI), lymph node involvement or peritoneal cytology. However, significant correlations were found between loss of hMLH1 and a lower histological grade and the absence of LVI in patients with SEEA. CONCLUSIONS: According to these results, MSI and a loss of protein expression of hMLH1 and hMSH2 may be associated with the pathogenesis of SEEA. In addition, hMLH1 immunostaining might have a role as a prognostic parameter. Further research using a large number of cases is needed to confirm our observations.

Prognostic value of p16INK4a and p14ARF gene hypermethylation in human colon cancer.

The INK4a/ARF locus (9p21) encodes two unique and unrelated cell cycle regulators, p16INK4a and p14ARF. This study was performed to evaluate the methylation status of p16INK4a and p14ARF genes, as well as its association with p16 and p53 expression, microsatellite instability (MI) status, and various clinicopathologic parameters in sporadic colorectal cancer. Sixty-five cases of primary colorectal adenocarcinoma with a series of clinicopathological parameters were obtained. We performed methylation-specific PCR of p16INK4a and p14ARF genes in colorectal cancer paraffin blocks with its paired normal samples, as well as immunohistochemical stainings for p16 and p53, and MI analysis. Aberrant methylations of p16INK4a and p14ARF gene were present in 21 (32.3%) and 33 (50.8%) out of 65 cases, respectively. p16INK4a aberrant methylation was correlated with p16 negativity (P=0.021) and p53 overexpression (P=0.007). p16INK4a aberrant methylation was more frequently present in poorly differentiated adenocarcinomas (P=0.002). Aberrant methylation of p14ARF gene occurred more frequently in patients under 50 years of age and in left-sided colon cancers, and was not statistically significant. Compared with the group with simultaneous absence of methylation in both promoters, the group showing concomitant alterations in both p16INK4a and p14ARF genes (n=10) more frequently presented lymph node metastasis (P=0.020) and higher tumor grade (P=0.014). There was no correlation between p16INK4a and p14ARF gene hypermethylation or MI status. This study suggests that simultaneous hypermethylation of both p16INK4a and p14ARF genes is greater prognostic value in sporadic human colorectal cancer.

Identification of large-scale molecular changes of Autotaxin(ENPP2) knock-down by small interfering RNA in breast cancer cells.

To understand comprehensive molecular mechanisms by which Autotaxin (ENPP2) mediates, we identified large-scale molecular changes responsible for aberrant expression of Autotaxin (ATX) on breast cancer cells by using DNA microarrays. Transcriptional over-expression of ENPP2 gene was endogenously silenced by using RNA interference technique, and then recapitulated corresponding molecular changes in MDA435 breast cancer cells. Application of nonparametric Wilcoxon statistical analyses (P<0.05) and the selection criteria of 2-fold differential gene expression change resulted in the identification of 368 genes including 133 up-regulated and 235 genes under-expressed in ENPP2-silencing MDA435 cells. Most of the functional categories of identified genes are associated with cellular metabolism, cytoskeleton organization, transcription regulation, signal transduction as well as cellular organization and biogenesis. Our data suggest that the molecular signature identified by the ENPP2-silencing methods may represent potential candidates that can explain the complicated characteristics of ATX and may serve as biomarkers, for the development of molecular-targeting therapy, in human breast cancer.

Comparative analysis of expression profiling of early-stage carcinogenesis using nodule-in-nodule-type hepatocellular carcinoma.

BACKGROUND: Nodule-in-nodule-type hepatocellular carcinoma (NIN-HCC) is a useful model to illustrate the multi-step nature of hepatocarcinogenesis. To identify large-scale molecular change in early hepatocarcinogenesis, the expression profile of NIN-HCC was compared with those from three sets of individual high-grade dysplastic nodules (HGDN) and grade 1 hepatocellular carcinomas. METHODS: We compared expression profiles of inner grade 1 hepatocellular carcinoma nodules and peripheral HGDN in one case of NIN-HCC using spotted-oligonucleotide DNA microarray. The relevant outlier genes assumed to associate with early carcinogenesis in hepatocellular carcinoma were identified by comparative analysis of NIN-HCC and individual cases of HGDN and grade 1 hepatocellular carcinoma, respectively. RESULTS: From this analysis we extracted a total of 40 genes, consisting of 28 up-regulated genes and 12 downregulated genes, and more than a two-fold change in grade 1 hepatocellular carcinoma compared with HGDN. CONCLUSION: We assessed the expression profiles of pre-neoplastic lesions and grade 1 hepatocellular carcinoma using oligonucleotide microarray analysis and found high stringent outlier genes that are presumably directly involved in the transition from dysplastic nodule to the early stage of hepatocellular carcinoma by utilizing NIN-HCC.

Autotaxin (lysoPLD/NPP2) protects fibroblasts from apoptosis through its enzymatic product, lysophosphatidic acid, utilizing albumin-bound substrate.

Autotaxin (ATX) was originally identified as a potent tumor cell motility-stimulating factor that displays multiple enzymatic activities including ATPase, Type I nucleotide pyrophosphatase/phosphodiesterase, and lysophospholipase D, depending on its substrates. We demonstrate herein that ATX is a key regulator of extracellular lysophosphatidic acid (LPA) that can act as survival factor, in addition to its mitogenic activity in mouse fibroblasts. Introduction of atx gene into NIH3T3 cells resulted in resistance to conditional apoptosis induced by serum-deprivation, and exogenous ATX protein prevented cells from death by starvation. Flow cytometric analysis showed that co-treatment of ATX with lysophosphatidylcholine as substrate rescued NIH3T3 cells from cellular apoptosis, and this survival activity of ATX was also demonstrated by caspase-3 degradation and PARP cleavage resulting from the enzymatic activity of extracellular ATX. Furthermore, the effect of ATX in preventing apoptosis appears to be mediated through the G-protein-coupled receptor pathway followed by the activation of phosphoinositide 3-kinase and Akt pathway leading to enhanced cell survival. These findings provide novel insights into understanding the functions of ATX as a key regulator of bioactive phospholipids and suggest interventions to correct dysfunction in conditions of tumor cell growth and metastasis.

Gefitinib trial in a fanconi's anemia patient with multiple squamous cell carcinomas and hepatocellular carcinoma.

FA (Fanconi's Anemia) is an autosomal recessive disorder that is characterized by pancytopenia with bone marrow hypoplasia, diverse congenital abnormalities and an increased predisposition towards malignancy. The mainstay of the treatment for these cancers has been surgery, because of the hypersensitive reactions of FA patients to DNA cross- linking agents or radiation. Therefore, there has been no effective therapy for advanced squamous cell carcinoma. We report here on a patient suffering from advanced multiple squamous cell carcinoma and hepatocellular carcinoma along with an FA, and this patient was treated with gefitinib.

Renal cell carcinoma in South Korea: a multicenter study.

The incidence of renal cell carcinoma (RCC) in South Korea is steadily becoming similar to that in Western countries. This study summarizes the results of a 3-year multicenter survey of RCC in South Korea, conducted by the Korean Genitourinary Pathology Study Group. A total of 795 cases of RCC were collected from 20 institutes between 1995 and 1997, including 686 clear cell RCCs (86.3%), 58 papillary RCCS (7.30%), 49 chromphobe RCCs (6.16%), and 2 collecting duct RCCs (0.25%). At least 5 years of follow-up was available for 627 clear cell, 54 papillary, and 49 chromophobe RCCs. All subtypes presented most frequently with stage T3aN0M0 at the time of operation, and papillary RCCs demonstrated more frequent lymph node metastasis. Overall survival was not significantly related to the histological subtype (clear cell vs papillary, P = 0.8651; clear cell vs chromophobe, P = 0.0584; papillary vs chromophobe, P = 0.0743). For clear cell RCCs, statistically significant associations were found between overall survival and sex (P = 0.0153), multiplicity (P = 0.0461), necrosis (P = 0.0191), age, sarcomatoid change, TNM stage, nuclear grade, and modality of treatment (all P <0.0001). Overall survival was significantly associated with tumor size (P = 0.0307), nuclear grade (P = 0.0235), multiplicity, sarcomatoid change, and TNM stage (all P <0.0001) for papillary RCCs and with the presence of sarcomatoid change (P = 0.0281), nuclear grade (P = 0.0015), treatment modality (P = 0.0328), and TNM stage (P <0.0001) for chromophobe RCCs. Age (P = 0.0125), nodal stage (P = 0.0010), and treatment modality (P = 0.0001) were significant independent prognostic indicators for clear cell RCC on multivariate analysis. This is the first multicenter study of RCC in South Korea, demonstrating the general patterns and prognostic factors of Korean RCCs.

Sarcomatoid hepatocellular carcinoma with hepatoblastoma-like features in an adult.

A mixed epithelial and mesenchymal tumor of the liver arising in an adult is rare and is mostly classified as sarcomatoid hepatocellular carcinoma (HCC). In this study, a case of sarcomatoid HCC in an adult with hepatoblastoma (HB)-like features, which produced difficulty in the differential diagnosis between sarcomatoid HCC and mixed HB, is presented. The epithelial component of the tumor composed of poorly differentiated HCC, Edmondson's grade III, and more primitive components, which were embryonal and small cell undifferentiated components of HB-like areas. The small undifferentiated cells surrounded HCC and the embryonal component of HB-like area, and revealed transition partly to areas of rhabdomyosarcoma. A small portion of chondrosarcoma was also noted. Immunohistochemical analysis showed that HCC and the embryonal component of HB-like areas expressed alpha-fetoprotein (AFP) and cytokeratin 8. The small undifferentiated cells were negative for AFP but stained with cytokeratin 8 as well as CD56, which is a marker of primitive cells in many sarcoma and HB. It is not certain whether small undifferentiated cells belong to hepatic progenitor cells or primitive mesenchymal cells. Polymerase chain reaction-single-strand conformation polymorphism analysis for beta-catenin mutation using microdissection revealed no mutation of any components. A review was undertaken of the cases previously reported as adult hepatoblastoma without detailed immunohistochemical study and consider many of them may be sarcomatoid HCC. These primitive and sarcomatoid components would be arising from the dedifferentiation process of HCC.

Ectopic hamartomatous thymoma: a case report showing CD99+ lymphocytes and a low proliferation index.

Ectopic hamartomatous thymoma is a rare benign tumor that consists of spindle, epithelial, and adipose cell elements. We present a case of this lesion arising in the supraclavicular region of a 59-year-old man, including the characteristic immunohistochemical and ultrastructural findings. DNA flow cytometry revealed diploidy with a low proliferation index (6.73%). The tumor contained CD99+ lymphocytes; CD99 (MIC2) can serve as a useful marker of immature T cells. These findings suggest that ectopic hamartomatous thymoma may develop from the third branchial pouch or thymic anlage.

Correlation of mutation and immunohistochemistry of p53 in hepatocellular carcinomas in Korean people.

The degree of correlation between sequencing and immunohistochemisty (IHC) for detecting mutations of p53 has not been well established in human hepatocellular carcinoma (HCC). We analyzed 36 HCCs from Korean people for p53 mutation at exons 4-10 by PCR-SSCP and sequencing, and compared the results with the IHC positivity. p53 mutations were identified in 7 out of 36 HCCs (19.4%). These mutations were found widely throughout exons 4-8. No mutation was detected in codon 249. Among the 7 mutations, 6 missense mutations were detected in 15 HCCs with > or =5% immunoreactive tumor cells and one nonsense mutation was in 21 HCCs with <5% immunoreactive tumor cells. The sensitivity for p53 mutation was 85.7% (6/7), the specificity 69.0% (20/29), the predictive value of positive IHC 40.0% (6/15), and the predictive value of negative IHC 95.2% (20/21). Two missense mutations were detected in 25 cases with <10% immunoreactive tumor cells. Predictive values of both positive IHC and negative IHC were higher in > or =5% overexpression group than in > or =10% overexpression group or >0% overexpression group. This study suggests that 5% immunoreactivity is a reliable immunohistochemical threshold value to detect p53 mutations in HCCs and the spectrum of p53 mutations in HCCs in Korean people is different from that of high aflatoxin B1 exposure areas.

Alterations of Fas-pathway genes associated with nodal metastasis in non-small cell lung cancer.

Many types of cancer cells are resistant to Fas-mediated apoptosis by several mechanisms, including the mutations of the genes involved in Fas-mediated apoptosis. In this study, to explore the possibility that the mutations of the genes involved in the proximal pathway of Fas-mediated apoptosis (Fas, FADD, caspase 8 and caspase 10) are involved in cancer metastasis, we have analysed somatic mutation and deletion of these genes in 80 non-small cell lung cancers (NSCLCs) with (n=43) and without (n=37) metastasis to the regional lymph nodes. We found 12 mutations (four Fas, four FADD, and four caspase 10 mutations) in 11 of 80 NSCLCs (13.8%). Interestingly, of these mutations, most mutations (10 out of 12) were detected in the NSCLCs with metastasis, and the frequency in the metastasis lesions (23%) was higher than that in the primary lesions of the NSCLCs without metastasis (5.4%). Furthermore, transfection study revealed that the tumor-derived mutants have decreased apoptosis inductions compared to the wild types. These data suggest that the inactivating mutations of the genes in the proximal pathway of Fas-mediated apoptosis may lead to a decreased cancer cell death and play a role in the metastasis of NSCLC.

Inactivating mutations of CASP10 gene in non-Hodgkin lymphomas.

Caspase 10 (Mch4/FLICE2) is a caspase homologous to caspase 8. A recent report described that inherited CASP10 gene mutations underlie defective lymphocyte and dendritic cell apoptosis in autoimmune lymphoproliferative syndrome (ALPS). In this study, to explore the possibility that mutation of this gene might be involved in the development of non-Hodgkin lymphoma (NHL), we have analyzed the entire coding region and all splice sites of the CASP10 gene for the detection of somatic mutations in 117 human NHLs. Overall, 17 NHLs (14.5%) were found to have CASP10 mutations, which were identified in the coding regions of the prodomain (n = 3), the p17 large protease subunit (n = 11), and the p12 small protease subunit (n = 3). We expressed the tumor-derived caspase 10 mutants in 293 cells and found that apoptosis was suppressed. These data suggest that the inactivating mutations of the CASP10 gene might lead to the loss of its apoptotic function and contribute to the pathogenesis of some human NHLs.

Inactivating mutations of the caspase-10 gene in gastric cancer.

We have analysed the genetic alteration of the entire coding region and all splice sites of caspase-8 and -10 genes in 99 gastric cancers by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP) and sequencing. We found LOH of the caspase-8 and -10 in nine (28%) of 32 and in four (15%) of 26 informative cases, respectively. Overall, three of 99 gastric cancers (3%) were found to have the caspase-10 mutations, which were identified in the coding regions of the death effector domain (codon 147) and the p17 large protease domain (codons 257 and 410), whereas no mutation was detected in caspase-8. In vitro expression studies, the M147T and Q257stop mutants severely impaired caspase-10-mediated apoptosis, whereas the V410I which was the same mutation detected in ALPS patient had a significant, albeit less severe, effect on apoptosis. The data presented here suggest that somatic alterations of the caspase-10 gene might contribute to the pathogenesis in a subset of gastric cancers through the loss of their apoptotic function.

Genetic analysis of the liver putative tumor suppressor (LPTS) gene in hepatocellular carcinomas.

Recently, a novel liver-related putative tumor suppressor (LPTS), which has a growth inhibitory function in the hepatocellular carcinoma (HCC) cell line, has been identified at chromosome 8p23. To determine the relationship of the LPTS with the development or progression of HCC, we analyzed the genetic alterations and the expression pattern of the LPTS gene in a series of 80 HCCs, six dysplastic nodules, and eight large regenerating nodules, determining the genomic structures. We identified a total of seven exons, of which two were alternative, and three LPTS isoforms, short (LPTS-S), medium (LPTS-M), and long-sizes (LPTS-L). In the genetic alteration study of the LPTS gene, no mutation was detected in the large regenerating nodules, dysplastic nodules, and HCC, whereas ten (34.5%) of 29 informative cases at one or more intragenic polymorphic sites showed loss of heterozygosity (LOH). Interestingly, LOH was identified only in HCC samples with hepatitis B virus (HBV) infection and the frequency of LOH was not statistically related with histologic grade and clinical stage, suggesting that allelic loss of the LPTS gene may occur as an early event in the development of HCC, especially in the cases with HBV infection.