Decreased expression of galectin-3 is associated with metastatic potential of liver fluke-associated cholangiocarcinoma

Galectin-3, a beta-galactoside-binding lectin, is a multifunctional protein implicated in a variety of biological functions, including tumour cell adhesion, proliferation, differentiation, cancer progression and metastasis. The present study was performed to clarify the impact of galectin-3 expression on patients with liver fluke-associated cholangiocarcinoma. Galectin-3 expression was examined immunohistochemically in 53 patients with intrahepatic cholangiocarcinoma, who had undergone surgery without pre-operative therapy. All bile duct epithelium expressed galectin-3 with different intensities, according to the different histological subtypes. The poorly-differentiated type expressed galectin-3 less intensely than the papillary, well- to moderately-differentiated types (P=0.012). We observed the association of low galectin-3 expression with lymphatic invasion (P=0.002). Suppression of galectin-3 expression in two human cholangiocarcinoma cell lines using siRNA targeted to galectin-3 significantly increased cell migration and invasion without alterations in cell proliferation. Regulation of galectin-3 expression may therefore be an alternative therapeutic approach to control metastasis of cholangiocarcinoma.     

PRKAR1A is overexpressed and represents a possible therapeutic target in human cholangiocarcinoma

The protein kinase A regulatory subunit 1 alpha (PRKAR1A/PKAI) pathway is overexpressed in varieties of tumors and cancer cell lines including cholangiocarcinoma (CCA), although its role in CCA growth modulation is unclear. In our study, we evaluated the effect of PRKAR1A/PKAI targeting on CCA cell proliferation. Real‐time PCR demonstrated an increased mRNA expression of PRKAR1A/PKAI, whereas protein kinase A regulatory subunit 2 beta (PRKAR2B/PKAII) was downregulated in human CCA tissues and CCA cell lines. Immunohistochemistry of human CCA tissues revealed increased PRKAR1A with decreased PRKAR2B protein expression. Moreover, CCA cell lines showed abundantly expressed PRKAR1A, while lacking PRKAR2B expression. Silencing PRKAR1A expression induced growth inhibition and apoptosis of CCA cells, with an associated decrease in mitogen‐activated protein kinases, PI3K/Akt, JAK/STAT and Wnt/β‐catenin pathway signaling. The inhibition of PKA using a PKA inhibitor and cAMP analogs also led to a significant cell growth inhibition. In conclusion, our study reports the overexpression as well as molecular mechanisms by which PRKAR1A/PKA regulates human CCA cell growth. Importantly, abrogation of gene expression caused significant CCA cell growth inhibition, oncogenic signaling and coupled apoptosis induction, suggesting PRKAR1A's potential as a drug target for CCA therapy.     

MAPK overexpression is associated with anthracycline resistance and increased risk for recurrence in patients with triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer is estimated to account for 15%-20% of all patients with breast cancer and is considered as a prognostically unfavorable subset. The aim of this study is to evaluate the prognostic impact of various molecular factors in patients with triple-negative breast cancer. PATIENTS AND METHODS: Tumor specimens from 109 patients with receptor-negative (estrogen receptor and progesterone receptor) breast cancer were analyzed for mitogen-activated protein kinase (MAPK), epidermal growth factor receptor (EGFR) and phosphoinositol-3-kinase (PI3K) expression by immunohistochemistry. The prognostic significance of these molecular factors, in addition to various prognostic variables, was investigated. RESULTS: Fifteen (13.8%), 38 (34.9%) and 33 patients (30.3%) had positive staining for EGFR, MAPK and PI3K, respectively. MAPK was associated with anthracycline resistance (P = 0.008) and lower MAPK score was significantly associated with shorter disease-free survival (P = 0.029). Survival following relapse was significantly worse for those with a higher MAPK score (P = 0.03). CONCLUSION: MAPK is a significant prognostic and predictive factor in patients with triple-negative breast cancer. Furthermore, the level of staining among those with a positive MAPK expression may play a prognostic role at different stages of relapse. Further translational research is required to elucidate molecular mechanisms of tumor proliferation in this subset of patients.     

Plasminogen activator inhibitor-1 polymorphism is associated with increased risk for oral cancer

In light of the recently observed contribution of thrombosis-related factors to carcinogenesis, we investigated the possible association of plasminogen activator inhibitor-1 (PAI-1) with increased risk for oral cancer. In DNA samples of 104 patients with oral squamous cell carcinoma and 106 healthy controls of comparable ethnicity, age and sex, we studied the 4G/5G polymorphism in the PAI-1 gene, which affects its expression. The mutant 4G allele and carrier frequencies were significantly increased in patients compared to controls (65.9% versus 49.5%; 88.5% versus 69.8% respectively, P<0.01). That increase was even higher in patients with a positive family history for thrombophilia or without one for cancer (P<0.001). Interestingly, significant difference from controls was observed only in patients with cancer stages I and II. These findings suggest that the 4G allele, by resulting in higher PAI-1 expression, is a major contributing factor in early stages of oral oncogenesis. Possibly, increased PAI-1 promotes initial development of oral cancer through regulation of cell detachment and delays further tumor progression by inhibiting vascularization.     

A polymorphism in the CDKN1B gene is associated with increased risk of hereditary prostate cancer

The loss of cell cycle control is believed to be an important mechanism in the promotion of carcinogenesis. CDKN1B (p27) belongs to the Cip/Kip family and functions as an important cell cycle gatekeeper. Several lines of evidence from clinical studies and laboratory experiments demonstrate that CDKN1B is an important tumor suppressor gene in prostate cancer etiology. In addition, a case-control study has shown that the 326T/G (V109G) polymorphism in CDKN1B is associated with advanced prostate cancer. In light of the evidence for linkage between the chromosomal location of the CDKN1B gene (12p13) and prostate cancer susceptibility in several hereditary prostate cancer (HPC) populations, we hypothesized that sequence variants of CDKN1B play a role in HPC. To test this hypothesis, we first resequenced this gene in 96 HPC probands to identify germ-line mutations and sequence variants. We then genotyped the identified sequence variants among all family members of 188 HPC families and tested for their cosegregation with prostate cancer. In total, 10 sequence variants were identified, including three nonsynonymous changes. A family-based test, which is free from the effects of population stratification, revealed a significant association between single nucleotide polymorphism (SNP) -79C/T and prostate cancer (with a nominal P of 0.0005). The C allele of -79C/T was overtransmitted from parents to their affected offspring. Evidence for this association was primarily contributed by affected offspring whose age at diagnosis was <65 years. Together with the previous association study in a sporadic prostate cancer population, our new findings additionally suggest that germ-line variants of this gene play a role in prostate cancer susceptibility.     

X-ray repair cross-complementing group 1 Arg194Trp polymorphism is associated with increased risk of lung cancer in Chinese Han population

There were many studies performed to assess the association between X-ray repair cross-complementing group 1 (XRCC1) Arg194Trp polymorphism and lung cancer risk in Chinese Han population, but contradictory results were reported. To provide a comprehensive and objective assessment of the association, a meta-analysis of all eligible case–control studies was carried out. After searching the databases and reading the abstracts, 12 case–control studies on the association between XRCC1 Arg194Trp polymorphism and lung cancer risk were finally included into this meta-analysis. Those 12 studies included a total of 4,385 cases and 4,545 controls. XRCC1 Arg194Trp polymorphism was associated with increased risk of lung cancer in Chinese Han population under three main models (allele contrast model, odds ratio (OR) = 1.12, 95 % confidence interval (CI) 1.00–1.26, P?=?0.049; homozygote model, OR = 1.27, 95 % CI 1.09–1.48, P?=?0.003; recessive model, OR = 1.26, 95 % CI 1.09–1.46, P?=?0.003). However, there was no obvious association between XRCC1 Arg194Trp polymorphism and lung cancer risk under the dominant model (OR = 1.06, 95 % CI 0.98–1.16, P?=?0.146). Sensitivity analysis suggested the stability and liability of this meta-analysis. Therefore, this meta-analysis suggests that XRCC1 Arg194Trp polymorphism is associated with increased risk of lung cancer in Chinese Han population.     

MSI in endometrial carcinoma: absence of MLH1 promoter methylation is associated with increased familial risk for cancers

Loss of DNA mismatch repair occurs in a variety of malignancies and is associated with genome-wide instability of microsatellite repeats, a molecular phenotype referred to as microsatellite instability (MSI). MSI is a consistent feature of colorectal and endometrial tumors from patients with hereditary non-polyposis colorectal cancer (HNPCC). Sporadic colorectal and endometrial cancers that exhibit MSI frequently have methylation of the MLH1 promoter. We undertook a detailed family and medical history study to compare family cancer risk for women with MSI-positive and -negative endometrial cancers. The MLH1 promoter methylation status was determined for all cancers. Family histories were developed for 80 probands (40 with MSI-positive and 40 with MSI-negative tumors). The numbers of reported cancers in first- and second-degree relatives of the 2 groups were similar. There was a modest increase in familial cancer clustering for MSI-positive probands. When MSI-positive tumors were subclassified according to MLH1 promoter methylation, a clear association between methylation status and familial cancer risk was evident. Women with MSI-positive endometrial cancers in which the MLH1 promoter was unmethylated had a 7-fold relative risk (RR) of demonstrating familial clustering of cancers [RR 7.07 (95% confidence interval 2.29-21.81)]. The women with MSI-positive, MLH1-unmethylated tumors were significantly younger than the rest of the study population (56.1 years vs. 65.4, p < or = 0.01). Age of onset and tumor MSI not associated with MLH1 promoter methylation may point to women with a genetic susceptibility to malignancies.     

UGT1A7 haplotype is associated with an increased risk of hepatocellular carcinoma in hepatitis B carriers

The UGT1A7 gene encodes UDP-glucuronosyltransferase, a key enzyme catalyzing the glucuronidation of various carcinogens. In this study, we investigated the association between haplotypes of the whole UGT1A7 gene and the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B. Sequence analysis of exon1 and the promoter region of the UGT1A7 gene was carried out to determine haplotype profiles for 244 patients with hepatocellular carcinoma, 223 hepatitis B carriers, and 314 healthy control subjects. Hepatitis B carriers with haplotypes other than haplotype 1 (Ht1; CTCTCGTG at –341, –57, 33, 387, 391, 392, 622, and 756) had a significantly greater risk of developing HCC with odds ratios (OR) of 1.67 (95% confidence interval [CI]; 1.11–2.52) for Ht1/others and 1.85 (95% CI; 1.09–3.14) for others/others. In multivariate logistic regression analysis including age and haplotypes from Ht1 to Ht4, the presence of Ht2 (CGAGAACG) or Ht4 (CTCGAATG) was associated with HCC risk (OR = 1.45 [95% CI; 1.03–2.03] and 4.95 [95% CI; 1.75–13.98], respectively). The results of this study show that the UGT1A7 haplotype is a suitable susceptibility marker for the development of HCC in hepatitis B carriers. ( Cancer Sci 2008; 99: 340–344)     

Glutathione S-transferase T1 null-genotype is associated with an increased risk of lung cancer

Glutathione S-transferases (GSTs) are involved in detoxification of carcinogens, e.g., from tobacco smoke. Therefore, polymorphisms in the GST genes have been considered as potential modifiers of individual cancer risk. In a population-based case-cohort study where cases and the subcohort sample were matched on duration of smoking, we investigated the occurrence of lung cancer and histological subtypes of lung cancer in relation to deletion polymorphism in both GSTM1 and GSTT1, single nucleotide polymorphisms (SNPs) in GSTP1 (Ile105Val and Ala114Val) and a 3 base pair deletion polymorphism in GSTM3. We further investigated the effects of the GST polymorphisms on lung cancer risk within subgroups of subjects defined by gender and age. The results showed a 2.4-fold (CI = 1.31-4.41) increased risk of lung cancer in GSTT1 null-genotype carriers but no significant effects of the polymorphisms in GSTM1, GSTM3, GSTP1-105 or GSTP1-114. The association was strongest in lower age groups, with a 9.6-fold increase in risk for subjects with the GSTT1 null-genotype in the 50-55 years age interval (CI = 3.03-30.59). Positive associations were found for GSTT1 within all major histological subtypes. Squamous cell carcinoma was the histological type most strongly associated with the GSTT1 genotype, with a 5.0-fold (CI = 2.26-11.18) increase in risk for subjects carrying the GSTT1 null-genotype. The effects of the GSTT1 null-genotype seemed stronger in the presence of the GSTM1 null-genotype or the GSTP1-105 variant allele. These results suggest that the GSTT1 null-genotype is associated with an increased risk of lung cancer, especially in younger individuals.     

Verapamil is associated with an increased risk of cancer in the elderly: the Rotterdam study

The association between the use of calcium channel blockers (CCB) and cancer has received ample attention, but is still controversial. In this study, we have tested the hypothesis that the observed association between CCB and cancer in earlier studies could be explained by residual confounding or by misclassification of exposure because of the use of cross-sectional data on drug use. Data from the Rotterdam Study, a prospective population-based cohort study in the municipal area Ommoord, were used. The study population consisted of a cohort of 3204 participants aged 71 years or older who were followed from a baseline interview in the period 1991-1993 for the occurrence of incident cancer. Data on drug use were gathered at baseline and through the seven community pharmacies which served the Ommoord region during the study period between 1 January 1991 and 1 January 1999. Incident cancer events were gathered from a nationwide registry of hospitalisation data and from a specialised cancer centre in the Rotterdam region. We performed three analyses. First, we followed the method, and adjusted for the same risk factors, as in the earlier studies. In the second analysis, we included all risk factors that were univariately associated with cancer in the Rotterdam Study. In the third analysis, we included exposure to CCBs as time-varying co-variates, while adjusting for potential confounders. The relative risk (RR) of cancer associated with CCB was 1.4 (95% Confidence Interval (CI): 0.9-2.0) in the first analysis and lowered to 1.2 (95% CI: 0.8-1.8) upon adjustment for the different co-variates in the second. In both analyses, however, verapamil was significantly associated with cancer with RRs of 2.1 (95% CI: 1.1-4.0) and 2.0 (1.01-3.9), respectively, whereas no associations were found with the other CCB in this study, i.e. diltiazem and nifedipine. A significantly increased risk of cancer was found for intermediate daily doses of verapamil and diltiazem. Intake of other antihypertensives such as beta-blocking agents, diuretics and ACE-inhibitors was not associated with cancer. In the third analysis with exposure to CCB as time-varying co-variates, the risk increase was non-significant for use of 2 years or less, 1.0 (95% CI: 0.7-1.5), and for use for a cumulative period of more than 2 years, 1.3 (95% CI: 0.8-2.0). However, in all models the hazard ratio was statistically significantly increased for verapamil, but not for diltiazem and nifedipine. On the basis of these analyses, we found no increase in cancer in users of diltiazem and nifedipine, nor in users of other antihypertensives. In line with earlier studies, however, we found an increased risk of cancer in users of verapamil. At variance with the conclusions from several other studies, we think that it is too early to conclude that CCB are not associated with cancer.     

Polymorphism of the insulin gene is associated with increased prostate cancer risk

High insulin levels are linked with increased cancer risk, including prostate cancer. We examined the associations between prostate cancer with polymorphisms of the insulin gene (INS) and its neighbouring genes, tyrosine-hydroxylase and IGF-II (TH and IGF2). In this study, 126 case-control pairs matched on age, race, and countries of origin were genotyped for +1127 INS-PstI in INS, -4217 TH-PstI in TH, and +3580 IGF2-MspI in IGF2. The homozygous CC genotype of +1127 INS-PstI occurred in over 60% of the population. It was associated with an increased risk of prostate cancer in nondiabetic Blacks and Caucasians (OR=3.14, P=0.008). The CC genotype was also associated with a low Gleason score <7 (OR=2.60, P=0.022) and a late age of diagnosis (OR=2.10, P=0.046). Markers in the neighbouring genes of INS showed only null to modest associations with prostate cancer. The polymorphism of INS may play a role in the aetiology of prostate cancer. Given the high prevalence of the CC genotype and its association with late age of onset of low-grade tumours, this polymorphism may contribute to the unique characteristics of prostate cancer, namely a high prevalence of indolent cancers and the dramatic increase in incidence with age.     

A novel founder CHEK2 mutation is associated with increased prostate cancer risk

Variants in the CHEK2 have been found to be associated with prostate cancer risk in the United States and Finland. We sequenced CHEK2 gene in 140 Polish patients with prostate cancer and then genotyped the three detected variants in a larger series of prostate cancer cases and controls. CHEK2 truncating mutations (IVS2 + 1G>A or 1100delC) were identified in 9 of 1921 controls (0.5%) and in 11 of 690 (1.6%) unselected patients with prostate cancer [odds ratio (OR) = 3.4; P = 0.004]. These mutations were found in 4 of 98 familial prostate cases (OR = 9.0; P = 0.0002). The missense variant I157T was also more frequent in men with prostate cancer (7.8%) than in controls (4.8%), but the relative risk was more modest (OR = 1.7; P = 0.03). I157T was identified in 16% of men with familial prostate cancer (OR = 3.8; P = 0.00002). Loss of the wild-type CHEK2 allele was not observed in any of prostate cancers from five men who carried CHEK2-truncating mutations. Our results provide evidence that the two truncating mutations of CHEK2 confer a moderate risk of prostate cancer in Polish men and that the missense change appears to confer a modest risk.     

Prospective study of cyclin D1 overexpression in Barrett's esophagus: association with increased risk of adenocarcinoma

BACKGROUND: Esophageal adenocarcinoma commonly arises from a precancerous condition, Barrett's esophagus, in which the normal squamous epithelium is replaced by a columnar cell-lined epithelium. Genetic alterations occurring in this process could serve as biomarkers for the risk of malignant progression, improve surveillance, and contribute to early diagnosis. We examined two potential biomarkers, cyclin D1 and p53, in a prospective cohort of Barrett's esophagus patients. METHODS: A total of 307 patients were enrolled in an endoscopic surveillance cohort, and esophageal biopsy specimens were collected at each endoscopy. Incident cases of adenocarcinoma were matched to control patients within the cohort by duration of follow-up, age, sex, and length of columnar cell-lined epithelium at recruitment. Biopsy specimens were analyzed for cyclin D1 and p53 protein levels by immunohistochemistry. Statistical tests were two-sided. RESULTS: A total of 12 cases of adenocarcinoma occurred within the follow-up period, and tumor biopsy specimens from 11 cases stained positive for cyclin D1. Biopsy specimens from eight of these patients taken at recruitment also stained positive for cyclin D1. A case-control analysis of biopsy specimens obtained at recruitment revealed a statistically significantly increased risk of progression to adenocarcinoma in Barrett's esophagus patients whose biopsy specimens were cyclin D1 positive (odds ratio [OR] = 6. 85; 95% confidence interval [CI] = 1.57-29.91; P =.0106) but not in patients whose biopsy specimens were p53 positive (OR = 2.99; 95% CI = 0.57-15.76; P =.197). CONCLUSIONS: Cyclin D1-positive staining could be a useful biomarker in identifying Barrett's esophagus patients at high risk of esophageal adenocarcinoma. Given the complexity of genetic alterations in the natural history of this cancer, additional biomarkers will be required to increase the sensitivity and specificity of molecular diagnosis.     

Protein kinase A effects of an expressed PRKAR1A mutation associated with aggressive tumors

Most PRKAR1A tumorigenic mutations lead to nonsense mRNA that is decayed; tumor formation has been associated with an increase in type II protein kinase A (PKA) subunits. The IVS6+1G>T PRKAR1A mutation leads to a protein lacking exon 6 sequences [R1 alpha Delta 184-236 (R1 alpha Delta 6)]. We compared in vitro R1 alpha Delta 6 with wild-type (wt) R1 alpha. We assessed PKA activity and subunit expression, phosphorylation of target molecules, and properties of wt-R1 alpha and mutant (mt) R1 alpha; we observed by confocal microscopy R1 alpha tagged with green fluorescent protein and its interactions with Cerulean-tagged catalytic subunit (C alpha). Introduction of the R1 alpha Delta 6 led to aberrant cellular morphology and higher PKA activity but no increase in type II PKA subunits. There was diffuse, cytoplasmic localization of R1 alpha protein in wt-R1 alpha- and R1 alpha Delta 6-transfected cells but the former also exhibited discrete aggregates of R1 alpha that bound C alpha; these were absent in R1 alpha Delta 6-transfected cells and did not bind C alpha at baseline or in response to cyclic AMP. Other changes induced by R1 alpha Delta 6 included decreased nuclear C alpha. We conclude that R1 alpha Delta 6 leads to increased PKA activity through the mt-R1 alpha decreased binding to C alpha and does not involve changes in other PKA subunits, suggesting that a switch to type II PKA activity is not necessary for increased kinase activity or tumorigenesis.     

Thymoma is associated with an increased risk of second malignancy.

BACKGROUND: An association between thymoma and second malignancy has been suggested but has not been validated. Whether the relation is due to treatment or to other thymoma-associated conditions is unclear. METHODS: The authors studied 192 consecutive patients with thymoma and compared the incidence of second malignancies with those of 206 patients who underwent thymectomy for nonthymomatous conditions and 1426 patients with nasopharyngeal carcinoma (NPC). Detailed clinicopathologic features of thymoma patients with second malignancies were described. RESULTS: Additional malignancies were detected in 15 of 192 patients (8%) during their clinical courses. The risk for those patients was significantly greater compared with the risk for patients with nonthymomatous conditions (adjusted odds ratio [OR], 3.81; 95% confidential intervals [95%CI], 1.05-13.81; P = 0.042) and patients with NPC (adjusted OR, 4.89; 95%CI, 2.26-10.53; P < 0.0001) after adjustment for age, gender, length of follow-up, myasthenia gravis, and radiation therapy. The occurrence of second malignancies did not correlate with histologic type or stage of thymoma, radiation therapy, or myasthenia gravis. CONCLUSIONS: Thymoma is associated with an increased risk of second malignancy. The association cannot be attributed to the effect of thymectomy or radiation therapy. Patients with thymoma, even if it is benign, should be followed regularly to facilitate the early detection of other malignancies.     

NQO1高表达提示宫颈癌预后不良

目的 探讨NQO1蛋白在宫颈癌中的表达及其临床意义。方法 免疫组化检测NQO1蛋白在123例宫颈癌标本的表达并比较其与临床病理学参数的相关性,Kaplan-Meier分析NQO1表达对患者无病生存期(DFS)和总生存期(OS)的影响,Cox分析宫颈癌的预后风险因素。结果 NQO1蛋白在宫颈癌中呈胞浆染色,其表达率明显高于正常宫颈组织,且NQO1高表达率与肿瘤组织分化、临床分期、淋巴结转移和HPV感染明显相关;NQO1高表达患者的DFS和OS均明显低于低表达者;NQO1高表达是宫颈癌患者预后不良的独立风险因素。结论 NQO1高表达可能是评估宫颈癌预后不良的生物学指标。     

c-MYC Asn11Ser is associated with increased risk for familial breast cancer

c-MYC is a multifaceted protein that regulates cell proliferation, differentiation and apoptosis. Its crucial role in diverse cancers has been demonstrated in several studies. Here, we analysed the influence of the rare c-MYC Asn11Ser polymorphism on familial breast cancer risk by performing a case-control study with a Polish (cases n = 349; controls n = 441) and a German (cases n = 356; controls n = 655) study population. All cases have been tested negative for mutations in the BRCA1 and BRCA2 genes. A joint analysis of the Polish and the German study population revealed a 54% increased risk for breast cancer associated with the heterozygous Asn11Ser variant (OR = 1.54, 95% CI 1.05-2.26, p = 0.028). The breast cancer risk associated with this genotype increases above the age of 50 years (OR = 2.24, 95% CI 1.20-4.21, p = 0.012). The wild-type amino acid Asn of this polymorphism is located in the N-terminal MYC transactivation domain and is highly conserved not only among most diverse species but also in the N-MYC homologue. Due to the pivotal role of c-MYC in diverse tumours, this variant might affect the genetic susceptibility of other cancers as well.