Fragile Histidine Triad Protein Expression Research Articles

FHIT mRNA and protein expression in hepatocellular carcinoma

Loss of fragile histidine triad (FHIT) gene expression is seen in approximately 50% of hepatocellular carcinomas in China. However, little information is available on FHIT expression in hepatocellular carcinoma in the United States, where carcinogen exposure is generally lower. Investigations of FHIT mRNA in hepatocellular neoplasms and paired non-neoplastic tissues demonstrated normal-sized FHIT transcripts in all non-neoplastic tissues and in all neoplasms including 11 hepatocellular carcinomas, two fibrolamellar carcinomas, and four benign proliferative lesions. In addition, all but one malignant and all benign neoplasms showed aberrant smaller transcripts. The smaller aberrant transcripts were overexpressed in 6/11 hepatocellular carcinomas and 1/2 fibrolamellar carcinomas. An additional 79 hepatocellular carcinomas, 12 fibrolamellar carcinomas and 15 hepatic adenomas were examined for FHIT expression by immunohistochemistry. No loss of immunostaining was seen in 67/79 (85%) of hepatocellular carcinomas, while a moderate or marked decrease was seen in 12/79 (15%). Fibrolamellar carcinomas and hepatic adenomas showed no loss of FHIT expression. In conclusion, hepatocellular carcinomas retained expression of normal FHIT mRNA transcripts, but also showed universal expression of smaller sized aberrant transcripts and commonly overexpressed these aberrant transcripts. Loss of FHIT protein expression is relatively uncommon in this cohort from the United States, where exposure to hepatic carcinogens is generally low.

Loss of FHIT protein expression is related to high proliferation, low apoptosis and worse prognosis in non-small-cell lung cancer

The fragile histidine triad (FHIT) gene, located at chromosome 3p14.2, is deleted in many solid tumors, including lung cancer. Its protein product is presumed to have tumor suppressor function. We investigated the incidence of loss of heterozygosity and loss of FHIT expression in a series of non-small-cell lung carcinomas and its correlation to apoptosis, proliferation index and prognosis. FHIT expression was determined by immunohistochemistry in formalin-fixed paraffin-embedded tissues from 54 squamous cell carcinomas (SCC) and 44 adenocarcinomas (AC) of the lung. DNA from frozen tumor and corresponding normal tissues were analyzed for allelic losses at two loci located internal (D3S1300, D3S1234) and three loci in flanking regions centromeric and telomeric (D3S1210, D3S1312, D3S1313) to the FHIT gene. Apoptosis was detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL). Proliferation index was determined with ki-67 and flow cytometric analysis. We correlated the results with tumor histology, prognosis and some immunohistochemical markers (p53, bcl-2, bax, c-myc, p21waf1, cyclin-D1). FHIT expression was related to tumor histology: 52 of 54 (96.3%) SCC and 20 of 44 (45.5%) AC were negative for FHIT (P<0.0001). We found LOH at 3p14.2 in 67.8% of the 98 cases: 72.3% of SCC and 61.4% of AC. Loss of FHIT expression was associated with a higher proliferation index (ki-67, P=0.007; flow cytometry, P<0.004) and lower apoptotic index (P=0.018). LOH at FHIT gene were associated to a high proliferation (flow cytometry, P<0.001) and lower apoptotic level (P=0.043). The log-rank test demonstrated a significant inverse correlation (P=0.039) between loss of FHIT expression and patient survival. FHIT plays an important role in the development of non-small-cell lung cancer, particularly in SCC. Loss of FHIT protein is correlated with a high proliferation and low apoptotic index in tumor cells, and is an independent prognostic indicator for the clinical outcome in patients with these tumors.

Fragile histidine triad gene expression and its corralation with mismatch repair protein in human sporadic colorectal carcinoma

Objective: To investigate the expression of fragile histidine triad (FHIT) gene and its correlation with clinicopathological features and correlation with mismatch repair protein (mainly MLH1 and MSH2) in human sporadic colorectal carcinoma (SCC). Methods: Immunohistochemistry SP method was used to determine the expression of FHIT, MLH1 and MSH2 protein in surgically resected specimens of 84 human SCC. Results: The positive rates of FHIT, MLH1 and MSH2 protein expression were 48.81%, 92.86% and 100% respectively. Loss or reduced expression of FHIT protein was not related with tumors clinicopathological features such as age, gender, tumors site and histological type (P>0.05), but was correlated with tumors invade depth, degree of the differentiation, Ducks’ stage and metastasis (P 0.05) and MSH2 protein (r=0.0000,P=1.00) expression in human SCC. Conclusion: Absent or reduction of FHIT gene expression consists of high proportion and is a frequent event in SCC. FHIT gene is involved in the development and progression of human SCC and may be a candidate tumors suppressor gene. The relationship between alteration of FHIT gene expression and mismatch repair protein (mainly MLH1 and MSH2) deserved further study in human SCC.

Effect of fragile histidine triad gene on apoptosis of MGC-803 gastric cancer cells

To investigate the effect of fragile histidine triad (FHIT) gene on the apoptosis of gastric cancer cells. FHIT gene was transfected into gastric cancer cell line MGC-803 by liposome. Western blot and immunohistochemical assay were employed to detect the expression of FHIT. Apoptosis and cell cycle were analyzed by flow cytometry (FCM). Morphological changes were observed by light and electron microscope. Stable expression of FHIT protein in transfected MGC-803 cells was obtained. The rates of G0/G1 phase and apoptosis cells were significantly higher in FHIT-transfected MGC-803 cells than those in control cells (64.4%compared with 49.5%and 32.0%compared with 12.2%, respectively). The results indicate that FHIT gene might be involved in the apoptosis of gastric cancer cells.

Decreased FHIT protein expression correlates with a worse prognosis in patients with diffuse large B-cell lymphoma

This study was conducted to evaluate the expression of the presumptive tumor suppressor gene, FHIT (fragile histidine triad) and its clinical significance in non-Hodgkin's lymphoma (NHL). Nine lymphoma cell lines, 62 NHL samples including 31 diffuse large B-cell lymphomas (DLBCLs), and 10 benign hyperplastic lymph nodes were analyzed for FHIT transcription using RT-PCR, with DNA sequencing performed where aberrant transcripts were found. Immunohistochemistry (IHC) studies were conducted for evaluation of FHIT protein expression with clinical data collected for assessment of the clinical relevance of the FHIT expression in DLBCLs. Eight of nine (88.9%) cell lines showed abnormal FHIT mRNA transcription, including 4 with co-existence of normal and aberrant transcripts, and 4 with absence of mRNA expression. Abnormal FHIT mRNA expression was noted in 10 (32.3%) DLBCL patients, including 3 with loss of FHIT mRNA expression and 7 with aberrant transcripts. In all NHLs, abnormal FHIT transcripts were determined for 17 of 62 patients (27.4%). Regarding the FHIT protein expression in DLBCLs, 41.9% showed strong FHIT IHC expression (2+), where 58.1% patients revealed reduced (1+) or absence (0) of FHIT protein. Decreased FHIT protein expression was associated with a worse survival after univariate and multivariate analysis. Our result indicates that abnormal FHIT mRNA expression is noted frequently in NHL cell lines and a certain proportion of NHL patients, and decreased FHIT protein expression indicates a significantly worse prognosis in DLBCLs.

Mechanism ofFHIT-Induced Apoptosis in Lung Cancer Cell Lines

Background : The FHIT (fragile histidine triad) gene is a frequent target of deletions associated with abnormal RNA and protein expression in lung cancer. Previous studies have shown FHIT gene transfer into lung cancer cell line lacking FHIT protein expression resulted in inhibition of tumor cell growth attributable to the induction of apoptosis and reversion of tumorigenecity. However, the mechanism of the tumor suppressor activity of the FHIT gene and the cellular pathways associated with its function are not completely understood. Methods :T o gain insight into the biological function of FHIT, we compared the NCI-H358 cell line with its stable FHIT transfectants after treatment with cisplatin or paclitaxel. We investigated the effects of FHIT gene expression on cell proliferation, apoptosis, and activation of caspase system and Bcl-2 family. The induction of apoptosis was evaluated by using DAPI staining and flow cytometry. Activation of caspases and Bcl-2 members was evaluated by Western blot analysis. Results :A significantly increased cell death was observed in FHIT transfectants after cisplatin or paclitaxel treatment and this was attributable to the induction of apoptosis. Remarkable changes in caspases and Bcl-2 family were observed in the transfected cells as compared with the control cells after treatment with paclitaxel. Activation of caspase-3 and caspase-7 was markedly increased in cells expressing FHIT. Expression level of Bcl-2 and Bcl-xL protein was significantly decreased and that of Bax and Bad protein was significantly increased in the transfected cells.

Fragile histidine triad protein expression in nonsmall cell lung cancer and correlation with Ki-67 and with p53.

Fragile histidine triad (FHIT) is a tumour suppressor gene, which is altered in a variety of epithelial tumours, including lung cancer. Biochemical and functional pathways of its tumourigenicity are not yet understood. Its role in tumour proliferation is particularly controversial. The purpose of this study was to correlate the expression of FHIT protein in nonsmall cell lung cancer (NSCLC) with tumour proliferation as estimated by Ki-67 antigen and with p53, a suppressor gene. FHIT, Ki-67 and p53 expression were evaluated by immunohistochemistry in 119 resected NSCLC. Altogether, 58 tumours were negative (expression <10%) for FHIT. The median expression in tumours was 15% positive cells, in comparison with 100% in normal matched lung tissue. The expression was as strong as in normal tissue in only 19 cases. FHIT expression was significantly lower in squamous cell carcinoma (SCC) (5%) than in adenocarcinoma (ADC) (64%). The median expression of Ki-67 was 20% and 69% of tumours were positives (expression >10%). Ki-67 expression was significantly higher in SCC (33.3%) than in ADC (10%). The loss of FHIT protein was not correlated with the expression of p53 (median: 7.5%, 58% of positive tumours for a cut-off of 10% of positive cells) or Ki-67. But percentage of labelled cells for p53 and Ki-67 were significantly correlated. The results suggest that for fragile histidine triad, the pathway of tumourigenesis is independent of p53 and of tumoural proliferation, as reported previously in vitro.

FHIT expression and hypermethylation in esophageal squamous cell carcinoma

The expression of the fragile histidine triad (FHIT) gene has been proposed to play an important role in early events of carcinogenesis and to be correlated with the progression or clinical outcomes of various cancers. Attention has focused recently on the regulation of FHIT expression, and loss of heterozygosity or hypermethylation of the CpG island in the promoter region has been suggested as clues to a possible mechanism. Methylation status and FHIT expression were investigated in the present study to clarify the clinicopathologic impact of FHIT in vivo. One hundred and five patients with esophageal cancer were admitted to the study. Cancer tissues were immunohistochemically stained for FHIT, and FHIT methylation status was examined in 36 patients by the methylation-specific polymerase chain reaction. FHIT methylation and expression were analyzed with respect to both clinicopathologic parameters and their interactions. Tissue specimens from 35 of the 105 patients (33.3%) stained positively for FHIT. In contrast, the CpG island in the FHIT promoter region was hypermethylated in 25 of the 36 (69.4%) analyzed cases of esophageal cancer. Hypermethylation was significantly correlated with the deletion of FHIT protein expression (P<0.001). FHIT hypermethylation was not associated with any clinicopathologic parameters. In contrast, deletion of FHIT expression significantly promoted tumor invasion (P<0.05) and lymphatic vessel invasion (P<0.01). Lymph node metastasis also appeared higher in the absence of FHIT protein expression, but the result was not significant (P=0.069). Patients with a preserved FHIT gene expression possibly exhibited an improved prognosis compared with those with deleted FHIT expression (P=0.093). Hypermethylation of the FHIT promoter region may be a mechanism for regulating FHIT expression. FHIT gene expression was closely correlated with cancer progression, as indicated by tumor invasion and lymphatic spread, and it may provide insight into the mechanism of progression of esophageal cancer.

Loss of FHIT protein expression correlates with disease progression and poor differentiation in gastric cancer.

The fragile histidine triad (FHIT) gene has recently been proposed as being a tumor suppressor gene. FHIT gene deletions or aberrant transcripts have been identified in a variety of human malignancies, including gastric carcinomas, suggesting that FHIT may play a key role in tumor development. However, the clinical impact of FHIT mutations in gastric carcinogenesis is still debated. Our purpose was to investigate whether FHIT expression in human primary gastric carcinoma is associated with the histological type, grade or stage of the tumor. We analyzed a well-characterized set of 137 primary gastric cancers. FHIT protein expression was evaluated in gastric mucosal samples, both from the tumor and tumor-free areas by immunohistochemistry. Furthermore, in a subgroup of 30 patients, FHIT mRNA expression was assessed by nested RT-PCR. Absent or reduced expression of FHIT protein correlated significantly with diffuse type ( P<0.0001), poor differentiation ( P<0.0001), and advanced stage ( P<0.0001) of gastric cancer. In contrast, FHIT protein was strongly expressed and uniformly distributed in tumor-free areas. The FHIT mRNA expression was absent or altered in diffuse and poorly differentiated carcinomas. These results show that the expression of FHIT in gastric carcinoma is related to the type, grade, and stage of the tumor. We suggest that FHIT expression may be considered a potential prognostic factor in gastric cancer.

Abnormal Fragile Histidine Triad Gene Expression in Gastric Cancer

Purpose: Genomic alterations and abnormal expression of the fragile histidine triad (FHIT) gene in gastric cancer were examined to determine whether the FHIT gene is actually a frequent target for alteration during gastric carcinogenesis. Materials and Methods: To correlate DNA and RNA lesions of the FHIT gene with the effect on FHIT protein expression, in 40 gastric cancers, we investigated the FHIT gene for loss of heterozygisity (LOH), aberrant transcripts, and protein expression. Results: Allelic loss at D3S1300 was detected in 7 of 38 () informative cases. Aberrant transcripts were observed in 20 of 40 () cases. Significant reduction of FHIT protein expression was observed in 22 of 40 () cases. Aberrant FHIT transcription was shown to be associated with loss of FHIT protein expression. However, aberrent FHIT transcripts themselves were not associated with any clinicopathological parameters, such as age, sex, tumor site, or clinical stage. Moreover, there was no association between the presence of LOH at D3S1300 and the expression of aberrant FHIT transcripts. Conclusion: The high frequency of aberrant FHIT transcripts, the significant rate of LOH at D3S1300, and the altered expression of the FHIT protein indicate that alterations of the FHIT gene can play an important role in gastric carcinogenesis.

Reciprocal translocations in breast tumor cell lines: cloning of a t(3;20) that targets the FHIT gene.

All molecular alterations that lead to breast cancer are not precisely known. We are evaluating the frequency and consequences of reciprocal translocations in breast cancer. We surveyed 15 mammary cell lines by multicolor fluorescence in situ hybridization (M-FISH). We identified nine apparently reciprocal translocations. Using mBanding FISH and FISH with selected YAC clones, we identified the breakpoints for four of them, and cloned the t(3;20)(p14;p11) found in the BrCa-MZ-02 cell line. We found that the breakpoint targets the potential tumor-suppressor gene FHIT (fragile histidine triad) in the FRA3B region; it is accompanied by homozygous deletion of exon 5 of the gene and absence of functional FHIT and fusion transcripts, which leads to the loss of FHIT protein expression. Additional experiments using comparative genomic hybridization provided further information on the genomic context in which the t(3;20)(p14;p11) reciprocal translocation was found.

FHIT expression in clear cell renal carcinomas: versatility of protein levels and correlation with survival.

Clear cell renal cell carcinomas (RCCs) are characterized by a deletion of chromosome 3p, which might result in the inactivation of the FHIT (fragile histidine triad) gene, a putative tumour suppressor gene. To explore the relevance of FHIT aberrations for tumour progression and prognosis in clear cell RCCs, FHIT protein expression was analysed in formalin-fixed tissue from 149 clear cell RCCs by immunohistochemistry. FHIT protein expression was found to be markedly reduced in all RCCs, when compared with adjacent non-neoplastic tubule epithelia. Although remaining below the FHIT levels of normal tubule epithelia, a significant increase of FHIT expression became evident from well (G1) to poorly (G3) differentiated clear cell RCCs (p=0.0001) and from low (pT1) to advanced (pT3) tumour stages (p=0.001). The log-rank test demonstrated a significant inverse correlation (p=0.0074) between FHIT expression and tumour aggressiveness as indicated by patient survival. Cox regression analysis revealed that FHIT expression is an independent prognostic parameter (p=0.0139) in clear cell RCCs. In conclusion, clear cell RCCs show a marked reduction of FHIT protein expression when compared with their putative cells of origin. In contrast to other tumour types, however, loss of FHIT protein expression is significantly less pronounced in poorly differentiated RCCs or advanced tumour stages. This versatility of FHIT expression during tumour progression suggests a role for reversible mechanisms of FHIT inactivation during the initiation and progression of clear cell RCCs.

Abnormal FHIT expression profiles in cervical intraepithelial neoplastic (CIN) lesions.

Abnormal fragile histidine triad transcripts were found in 20–30% of CIN2/3 lesions and 11% of normal cervical biopsies by RT–PCR. Bi-allelic loss of the fragile histidine triad gene and the loss of fragile histidine triad protein expression detectable by immunochemical staining with a polyclonal fragile histidine triad specific antibody was rare. The genomic changes showed no association with the presence of human papillomavirus types which carry high risk for cervical cancer (high risk human papillomavirus) as assessed by a type-specific multiplex PCR. The presence of abnormal fragile histidine triad transcripts in a subset of CIN2/3 lesions with no high risk human papillomavirus suggests that this could be an independent risk factor associated with an alternative carcinogenic pathway.British Journal of Cancer (2002) 86, 376–381. DOI: 10.1038/sj/bjc/6600077 www.bjcancer.com© 2002 The Cancer Research Campaign

Aberration of FHIT Gene is Associated with Increased Tumor Proliferation and Decreased Apoptosis—Clinical Evidence in Lung and Head and Neck Carcinomas

Human FHIT (fragile histidine triad) gene is highly conserved gene homologous to a group of genes identified in prokaryotes and eukaryotes. Loss of FHIT function may be important in the development and/or progression of various types of cancer. We undertook a clinical study to analyze the relation between aberrant function of FHIT gene, tumor cell proliferation, and intensity of apoptosis as well as prognostic output in lung and squamous cell head and neck carcinoma (HNSCC). Status of FHIT gene, expression of p21waf1, intensity of apoptosis, and cell proliferation were analyzed in HNSCC and lung carcinoma tissues by molecular genetic methods, immunohistochemistry, [3H]-thymidine labeling method, and FACScan analysis in frozen and paraffin-embedded tissue sections. The majority of the malignant lung and HNSCC lesions displayed aberrant expression of FHIT gene, followed by low or negative expression of p21waf1, and increased intensity of cell proliferation. Similar results were obtained on synchronous combinations of normal, precancerous, and cancerous head and neck tissues. The observed changes increased with progression of these lesions. We examined tumor and corresponding normal tissue samples for microsatellite markers D3S1300 and D3S4103 to evaluate the loss of heterozygosity (LOH) at the FHIT gene loci. We found high percentage of LOH in both lung tumors and HNSCC (75% for D3S1300 and 79% for D3S4103 in lung cancer, and 87% for D3S1300 and 78% for D3S4103 in HNSCC). The median survival time of the patients suffering from lung cancer without FHIT protein expression was 22.46 months and that of the patients with FHIT expression 36.04 months. FHIT-negative cases tended to correlate with a worse prognosis, but this was not statistically significant. Median survival time of HNSCC patients without FHIT protein expression was 30.86 months and that of the patients with FHIT expression was 64.04 months (p < 0.05). Our results show a correlation between aberrant FHIT expression, a low rate of apoptosis, and high tumor cell proliferation. Aberrant FHIT gene could be a prognostic marker in lung cancer.

Altered Expression of the Fragile Histidine Triad Gene in Primary Gastric Adenocarcinomas

Genomic alterations and abnormal expression of the fragile histidine triad (FHIT) gene in gastric carcinomas were examined to determine whether the FHIT gene is actually a frequent target for alteration during gastric carcinogenesis. To correlate DNA and RNA lesions of the FHIT gene with the effect on FHIT protein expression, we have investigated the FHIT gene for loss of heterozygosity (LOH), aberrant transcripts, point mutations, and protein expression in 35 gastric adenocarcinomas. Allelic loss at D3S1300 was detected in 7 of 33 (21%) informative cases. Aberrant transcripts, with deletions and/or insertions, were observed in 20 of 35 (57.1%) cases and resulted from alternative splicing through exon skipping and/or insertion of the FHIT intron 5 sequence or activation of the cryptic splice site. Point mutations were not found in the FHIT coding region but detected in noncoding exon 2, 3, 4, or 5 of eight aberrant transcripts. Significant reduction of FHIT protein expression was observed in 22 of 35 (62.9%) cases. Aberrant FHIT transcription was shown to be associated with loss of FHIT protein expression. However, aberrant FHIT transcripts themselves were not associated with any clinicopathological parameters, such as age, sex, tumor site, or clinical stage. Moreover, there was no association between the presence of LOH at D3S1300 and the expression of aberrant FHIT transcripts. Nevertheless, high frequency of aberrant FHIT transcripts, significant rate of LOH at D3S1300, and altered expression of the FHIT protein indicate that alterations of the FHIT gene can play an important role in gastric carcinogenesis.

Loss of fragile histidine triad gene expression is associated with progression of esophageal squamous cell carcinoma, but not with the patient's prognosis and smoking history

Recently, fragile histidine triad (FHIT) gene abnormality has been thought to be associated with several malignancies and smoking history. The authors previously discovered that methylation of the 5' CpG island of the FHIT gene was closely associated with transcriptional inactivation in esophageal squamous cell carcinoma (SCC); however, the clinical impact of the FHIT gene in esophageal carcinoma is still unknown. In this article, the authors evaluated the clinical impact of the FHIT gene in 149 esophageal squamous cell carcinoma (SCC) patients retrospectively using immunohistochemical analysis. They also examined the correlation between FHIT protein expression and smoking history. Among 149 curative resection (R0) cases of esophageal SCC, normal FHIT protein expression was noted in only 33 cases (22.1%), whereas reduced FHIT protein expression was noted in 67 cases and there was no FHIT expression in 50 cases. When a tumor invaded the muscle layer, FHIT protein expression was markedly reduced. The cases with reduction or loss of FHIT protein expression tended to have poor prognoses (P = 0.069). However, Cox multivariate analysis revealed that FHIT protein reduction had no relation to prognosis. FHIT protein expression had no relation to smoking history. FHIT protein expression was associated with progression of esophageal SCC, however, it may not be associated with the patient's prognosis and smoking history.

Loss of fragile histidine triad gene expression is associated with progression of esophageal squamous cell carcinoma, but not with the patient's prognosis and smoking history

BACKGROUND Recently, fragile histidine triad (FHIT) gene abnormality has been thought to be associated with several malignancies and smoking history. The authors previously discovered that methylation of the 5′ CpG island of the FHIT gene was closely associated with transcriptional inactivation in esophageal squamous cell carcinoma (SCC); however, the clinical impact of the FHIT gene in esophageal carcinoma is still unknown. METHODS In this article, the authors evaluated the clinical impact of the FHIT gene in 149 esophageal squamous cell carcinoma (SCC) patients retrospectively using immunohistochemical analysis. They also examined the correlation between FHIT protein expression and smoking history. RESULTS Among 149 curative resection (R0) cases of esophageal SCC, normal FHIT protein expression was noted in only 33 cases (22.1%), whereas reduced FHIT protein expression was noted in 67 cases and there was no FHIT expression in 50 cases. When a tumor invaded the muscle layer, FHIT protein expression was markedly reduced. The cases with reduction or loss of FHIT protein expression tended to have poor prognoses (P = 0.069). However, Cox multivariate analysis revealed that FHIT protein reduction had no relation to prognosis. FHIT protein expression had no relation to smoking history. CONCLUSIONS FHIT protein expression was associated with progression of esophageal SCC, however, it may not be associated with the patient's prognosis and smoking history. Cancer 2000;89:5–11. © 2000 American Cancer Society.

Fragile histidine triad gene expression in primary prostate cancer and in an in vitro model

BACKGROUND The fragile histidine triad (FHIT) is frequently deleted and altered in many human cancers. Replacement of the FHIT gene into cancer cell lines lacking FHIT expression results in loss of tumorigenicity and tumor growth. METHODS We investigated the status and function of the FHIT gene in the etiology of prostate carcinoma, utilizing human prostate cancer tissues and cell lines and the multistep human prostate epithelial (HPE) cell tumor model. RESULTS In primary cancers, either no FHIT protein expression or greatly reduced expression was observed in the tumor cells, while FHIT was expressed at high levels in the adjacent normal prostate epithelia. No aberrant FHIT transcripts were observed in normal HPE cells. Aberrant transcripts were observed in the immortalized and nontumorigenic HPV-18 C-1 cell line. A tumor cell line (129 Nu 5002-1) derived from chemical transformation of HPV-18 C-1 cells did not express the FHIT gene. Immunoblot analysis of FHIT protein levels confirmed the absence of FHIT expression in the 129 Nu 5002-1 tumor cell line. Among the metastatic prostate cancer cell lines, PC-3, DU-145, and S7 exhibited aberrant transcripts, but the LNCaP cell line (early passage) was normal. Upon cloning of the cDNA and determining the DNA sequence of the PCR fragments, we observed specific alterations such as deletions and insertions in the aberrant transcripts. A majority of prostate cancer cell lines expressed the normal-sized transcript in addition to the aberrant transcripts. CONCLUSIONS Our results indicate that alterations in the FHIT gene represent an early event in prostate carcinogenesis. Prostate 43:101–110, 2000. © 2000 Wiley-Liss, Inc.

Fragile histidine triad gene expression in primary prostate cancer and in an in vitro model.

The fragile histidine triad (FHIT) is frequently deleted and altered in many human cancers. Replacement of the FHIT gene into cancer cell lines lacking FHIT expression results in loss of tumorigenicity and tumor growth. We investigated the status and function of the FHIT gene in the etiology of prostate carcinoma, utilizing human prostate cancer tissues and cell lines and the multistep human prostate epithelial (HPE) cell tumor model. In primary cancers, either no FHIT protein expression or greatly reduced expression was observed in the tumor cells, while FHIT was expressed at high levels in the adjacent normal prostate epithelia. No aberrant FHIT transcripts were observed in normal HPE cells. Aberrant transcripts were observed in the immortalized and nontumorigenic HPV-18 C-1 cell line. A tumor cell line (129 Nu 5002-1) derived from chemical transformation of HPV-18 C-1 cells did not express the FHIT gene. Immunoblot analysis of FHIT protein levels confirmed the absence of FHIT expression in the 129 Nu 5002-1 tumor cell line. Among the metastatic prostate cancer cell lines, PC-3, DU-145, and S7 exhibited aberrant transcripts, but the LNCaP cell line (early passage) was normal. Upon cloning of the cDNA and determining the DNA sequence of the PCR fragments, we observed specific alterations such as deletions and insertions in the aberrant transcripts. A majority of prostate cancer cell lines expressed the normal-sized transcript in addition to the aberrant transcripts. Our results indicate that alterations in the FHIT gene represent an early event in prostate carcinogenesis.

Aberrant FHIT mRNA transcripts are present in malignant and normal haematopoiesis, but absence of FHIT protein is restricted to leukaemia.

Aberrant FHIT mRNA transcripts are present in malignant and normal haematopoiesis, but absence of FHIT protein is restricted to leukaemia Alterations of the recently cloned fragile histidine triad (FHIT) gene at chromosome 3p14.2 are frequent in a variety of solid tumours and cancer cell lines. Based on these findings, FHIT has been proposed as a putative tumour-suppressor gene. We evaluated the mRNA expression of the FHIT gene in samples from 55 patients with various haematological malignancies (21 AML, 8 CML, 10 CLL, seven low-grade and nine high-grade Non-Hodgkin's lymphomas), in a panel of 16 leukaemia cell lines, in normal mature haematopoietic cells of both myeloid and lymphoid lineage, as well as in CD34+ haematopoietic progenitor cells. Aberrant FHIT mRNA transcripts were observed in 14/16 (88%) leukaemia cell lines, 43/55 (78%) primary haematological neoplasms, but also in 17/22 (77%) normal controls. 1/16 (6%) cell lines and 7/55 (13%) neoplasms did not express any FHIT mRNA. cDNA sequencing revealed exonic deletions, small DNA insertions and combinations of both. Analysis of genomic DNA showed gene deletions in two myeloid leukaemia cell lines. In contrast to all normal types of haematopoietic cells, FHIT protein was clearly reduced or absent in 8/18 (44%) neoplastic samples tested. Our data indicate that whilst aberrant FHIT mRNA transcripts are seen both in normal and malignant cells, lack of FHIT protein is restricted to leukaemia. Absent FHIT protein expression might contribute to leukaemogenesis.