Mesenchymal stem cell therapy for liver fibrosis need "partner": Results based on a meta-analysis of preclinical studies.

BACKGROUND: The efficacy of mesenchymal stem cells (MSCs) in treating liver fibrosis has been demonstrated in several clinical studies. However, their low survival and liver implantation rates remain problematic. In recent years, a large number of studies in animal models of liver fibrosis have shown that MSCs combined with drugs can improve the efficacy of MSCs in the treatment of liver fibrosis alone and inhibit its progression to end-stage liver disease. This has inspired new ways of thinking about treating liver fibrosis. AIM: To investigate the effectiveness and mechanisms of MSCs combined with drugs in treating liver fibrosis. METHODS: Data sources included four electronic databases and were constructed until January 2024. The subjects, interventions, comparators, outcomes, and study design principle were used to screen the literature, and the quality of the literature was evaluated to assess the risk of bias. Relevant randomised controlled trials were selected, and the final 13 studies were included in the final study. RESULTS: A total of 13 studies were included after screening. Pooled analysis showed that MSCs combined with drug therapy significantly improved liver function, promoted the repair of damaged liver tissues, reduced the level of liver fibrosis-related indexes, and effectively ameliorated hepatic fibrosis by modulating the hepatic inflammatory microenvironment, promoting the homing of MSCs, and regulating the relevant signaling pathways, and the treatment efficacy was superior to MSCs alone. However, the combined treatment statistics showed no ame-lioration in serum albumin levels (standardized mean difference = 0.77, 95% confidence interval: -0.13 to 1.68, P = 0.09). CONCLUSION: In conclusion, MSCs combined with drugs for treating liver fibrosis effectively make up for the shortcomings of MSCs in their therapeutic effects. However, due to the different drugs, the treatment mechanism and effect also differ. Therefore, more randomized controlled trials are needed to compare the therapeutic efficacy of different drugs in combination with MSCs, aiming to select the "best companion" of MSCs in treating hepatic fibrosis.

Polyneuropathy organomegaly endocrinopathy M-protein and skin changes syndrome with ascites as an early-stage manifestation: A case report.

BACKGROUND: Polyneuropathy organomegaly endocrinopathy M-protein and skin changes (POEMS) syndrome is a rare paraneoplastic syndrome caused by a potential plasma cell tumor. The clinical manifestations of POEMS syndrome are diverse. Due to the insidious onset and lack of specific early-stage manifestations, POEMS syndrome is easily misdiagnosed or never diagnosed, leading to delayed treatment. Neurological symptoms are usually the first clinical manifestation, while ascites is a rare symptom in patients with POEMS syndrome. CASE SUMMARY: A female patient presented with unexplained ascites as an initial symptom, which is a rare early-stage manifestation of the condition. After 1 year, the patient gradually developed progressive renal impairment, anemia, polyserosal effusion, edema, swollen lymph nodes on the neck, armpits, and groin, and decreased muscle strength of the lower extremities. The patient was eventually diagnosed with POEMS syndrome after multidisciplinary team discussion. Treatment comprised bortezomib + dexamethasone, continuous renal replacement therapy, chest and abdominal closed drainage, transfusions of erythrocytes and platelets, and other symptomatic and supportive treatments. The patient's condition initially improved after treatment. However, then her symptoms worsened, and she succumbed to the illness and died. CONCLUSION: Ascites is a potential early manifestation of POEMS syndrome, and this diagnosis should be considered for patients with unexplained ascites. Furthermore, multidisciplinary team discussion is helpful in diagnosing POEMS syndrome.

Portal hypertension exacerbates intrahepatic portosystemic venous shunt and further induces refractory hepatic encephalopathy: A case report.

BACKGROUND: Intrahepatic portosystemic venous shunt (IPSVS) is a rare hepatic disease with different clinical manifestations. Most IPSVS patients with mild shunts are asymptomatic, while the patients with severe shunts present complications such as hepatic encephalopathy. For patients with portal hypertension accompanied by intrahepatic shunt, portal hypertension may lead to hemodynamic changes that may result in exacerbated portal shunt and increased shunt flow. CASE SUMMARY: A 57-year-old man, with the medical history of chronic hepatitis B and liver cirrhosis, was admitted to our hospital with abnormal behavior for 10 mo. He had received the esophageal varices ligation and entecavir therapy 1 year ago. Comparing with former examination results, the degree of esophageal varices was significantly reduced, while the right branch of the portal vein was significantly expanded and tortuous. Meanwhile, abdominal ultrasound presented the right posterior branch of portal vein connected with the retrohepatic inferior vena cava. The imaging findings indicated the diagnosis of IPSVS and hepatic encephalopathy. Instead of radiologic interventions or surgical therapies, this patient had only accepted symptomatic treatment. No recurrence of hepatic encephalopathy was observed during 1-year follow-up. CONCLUSION: Hemodynamic changes may exacerbate intrahepatic portosystemic shunt. The intervention or surgery should be carefully applied to patients with severe portal hypertension due to the risk of hemorrhage.

An Integrated Microarray Analysis Reveals Significant Diagnostic and Prognostic Biomarkers in Pancreatic Cancer.

BACKGROUND Pancreatic cancer (PAC) is a lethal cancer and it is essential to develop accurate diagnostic and prognostic biomarkers for PAC. MATERIAL AND METHODS An integrated microarray analysis of PAC was conducted to identify differentially expressed genes (DEGs) between PAC and non-tumor controls. Expression of DEGs were further confirmed by The Cancer Genome Atlas and the Genotype-Tissue Expression. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and protein-protein integration network construction were performed to further research the biological functions of DEGs. Receiver-operating characteristic analysis and survival analysis were used to evaluate the diagnostic and prognostic value of DEGs for PAC. RESULTS Seventeen microarray datasets were downloaded from Gene Expression Omnibus to conduct the integrated microarray analysis. A total of 1136 DEGs (596 upregulated and 540 downregulated DEGs) in PAC tissues compared with non-tumor controls were identified. Pancreatic secretion (Kegg: 04972), insulin signaling pathway (Kegg: 04910), and several cancer-related pathways including pathways in cancer (Kegg: 05200), MAPK signaling pathway (Kegg: 04010), and pancreatic cancer (Kegg: 05212) were enriched for DEGs in PAC. Seven DEGs (AHNAK2, CDH3, IFI27, ITGA2, LAMB3, SLC6A14, and TMPRSS4) were found to have both great diagnostic and prognostic value for PAC. High expression of these 7 DEGs were significantly associated with poor prognosis of patients with PAC. CONCLUSIONS These 7 DEGs might be potential diagnostic and prognostic biomarkers for PAC and help uncovering the mechanism of PAC.

The oncoprotein HBXIP competitively binds KEAP1 to activate NRF2 and enhance breast cancer cell growth and metastasis.

The nuclear factor E2-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 (KEAP1) signaling cascades is a key transcriptional pathway governing cellular oxidative stress and tumor development. Mammalian hepatitis B X-interacting protein (HBXIP) has critical roles in modulating cancer malignance and tumor progression. However, whether HBXIP interacts with KEAP1 and NRF2 is unclear. Here, we found that HBXIP can effectually compete with NRF2 for binding with KEAP1 protein via its highly conserved GLNLG motif. The HBXIP-mediated reduction in NRF2-KEAP1 complexes promotes NRF2 accumulation and nuclear entry, which facilities the activation of antioxidant response element (ARE)-dependent signaling cascades, thereby reducing the accumulation of endogenous cellular reactive oxygen species (ROS). We also found a strong positive correlation between HBXIP expression and NRF2 expression in breast cancer cells, tissue microarrays and clinical breast cancer tissues. Furthermore, this positive correlation was further confirmed via analysis of 1905 clinical cases of breast carcinoma provided by the cancer genomics database cBioPortal. Strikingly, disrupting the HBXIP-KEAP1 axis via mutating the GLNLG motif of HBXIP leads to potent inhibition of the malignancy of breast carcinoma both in vivo and in vitro. Our findings broaden our understanding of HBXIP as a modulation factor of cellular oxidative stress and address a novel regulatory mechanism governing redox homeostasis and the progression of breast carcinoma.

Diversity and bioactive potential of culturable fungal endophytes of Dysosma versipellis; a rare medicinal plant endemic to China.

The plant Dysosma versipellis is known for its antimicrobial and anticancer properties but is a rare and vulnerable perennial herb that is endemic to China. In this study, 224 isolates were isolated from various tissues of D. versipellis, and were classified into 53 different morphotypes according to culture characteristics and were identified by sequence analyses of the internal transcribed spacer (ITS) region of the rRNA gene. Although nine strains were not assignable at the phylum level, 44 belonged to at least 29 genera of 15 orders of Ascomycota (93%), Basidiomycota (6%), and Zygomycota (1%). Subsequent assays revealed antimicrobial activities of 19% of endophytic extracts against at least one pathogenic bacterium or fungus. Antimicrobial activity was also determined using the agar diffusion method and was most prominent in extracts from four isolates. Moreover, high performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry analyses (UPLC-QTOF MS) showed the presence of podophyllotoxin in two Fusarium strains, with the highest yield of 277 µg/g in Fusarium sp. (WB5121). Taken together, the present data suggest that various endophytic fungi of D. versipellis could be exploited as sources of novel natural antimicrobial or anticancer agents.

The LPI/GPR55 axis enhances human breast cancer cell migration via HBXIP and p-MLC signaling.

The G protein-coupled receptor 55 (GPR55) is expressed in multiple tissues, and has been implicated in cancer pathogenesis, but little is known about its role in the migratory behavior of cancer cells, particularly breast cancer cells. In this study we first showed that GPR55 expression levels in 38 metastatic lymph nodes of breast cancer patients were profoundly elevated, and were positively associated in human breast cancer cells with their migratory ability. Moreover, the plasma levels of GPR55 endogenous agonist L-a-lysophosphatidylinositol (LPI) were significantly increased in breast cancer patients compared with healthy individuals. In human breast cancer LM-MCF-7 and MDA-MB-231 cells, treatment with LPI (2.5 µmol/L) significantly increased filopodia formation and resulted in cell migration, which could be blocked either by the GPR55 antagonist CID16020046 or by siRNA-mediated GPR55 knockdown. Furthermore, dual-luciferase report gene assays showed that GPR55 upregulated HBXIP at the promoter; GPR55 expression levels were positively correlated with HBXIP expression levels in breast cancer tissues and 8 breast cancer cell lines. We also showed that the LPI/GPR55 axis promoted the migration of breast cancer cells via two mutually exclusive pathways - the HBXIP/p-ERK1/2/Capn4 and MLCK/MLC signaling pathways. In xenograft nude mouse model, loss of GPR55 mainly affected breast cancer cell metastasis and the formation of metastatic foci. Thus, GPR55 is involved in the migratory behavior of human breast cancer cells and could serve as a pharmacological target for preventing metastasis.

Inhibition of autophagy enhances effects of PF-04691502 on apoptosis and DNA damage of lung cancer cells.

Autophagy modulation has been considered as a potential therapeutic strategy for lung diseases. The PI3K-Akt-mTOR pathway may be one of the main targets for regulation of autophagy. We previously reported that a PI3K/mTOR dual inhibitor PF-04691502 suppressed hepatoma cells growth in vitro. However, it is still unclear whether PF-04691502 induces autophagy and its roles in DNA damage and cell death in human lung cancer cells. In this study, we investigate the effects of PF-04691502 on the autophagy and its correlation with cell apoptosis and DNA damage in non-small-cell lung cancer (NSCLC) cell lines. PF-04691502 efficiently inhibited the phosphorylation of Akt and showed dose-dependent cytotoxicity in A549 and H1299 cells. PF-04691502 also triggered apoptosis and the cleavage of caspase-3 and PARP. Phosphorylated histone H2AX (γ-H2AX), a hallmark of DNA damage response, was dramatically induced by PF-04691502 treatment. By exposure to PF-04691502, A549 cells acquired a senescent-like phenotype with an increase in the level of ß-galactosidase. Furthermore, PF-04691502 enhanced the expression of LC3-II in a concentration-dependent manner. More interestingly, effects of PF-04691502 on toxicity and DNA damage were remarkably increased by co-treatment with an autophagy inhibitor, chloroquine (CQ), in human lung cancer cells. These data suggest that a strategy of blocking autophagy to enhance the activity of PI3K/mTOR inhibitors warrants further attention in treatment of NSCLC cells.

[The polymorphisms of XRCC1 gene and susceptibility to pulmonary cancer].

OBJECTIVE: To explore the relationship between the polymorphisms of DNA repair gene XRCC1 and susceptibility to pulmonary cancer. METHODS: A case-control study of 209 lung cancer patients and 256 control subjects was conducted to investigate the role of XRCC1 gene in lung cancer. Genotyping was performed using PCR based restriction fragment length polymorphism (PCR-RFLP) technique. RESULTS: The frequency (19.1%) of XRCC1-194 Trp/Trp in case group was significantly higher than that (10.9%) in control group (P < 0.05), OR for lung cancer was 2.215 (95% CI: 1.276-3.845). The frequency (6.7%) of XRCC1-280 His/His in case group was significantly higher than that (4.3%) in control group (P < 0.05), OR for lung cancer was 2.46 (95% CI: 1.141-5.304). There was no significant difference for XRCC1-399 Gln/Gln genotype between the two groups. Interaction analysis of gene polymorphisms and environment factors indicated that there was interactions between XRCC1-194 Trp/Trp and XRCC1-280 His/His genotypes and smoking. The risks of lung cancer in smokers with XRCC1-194 Arg/Trp+Trp/Trp and XRCC1-280 His/His+Arg/His were 4.889 (95% CI: 2.828-8.452) and 6.281(95% CI: 3.572-11.046), respectively. CONCLUSION: These findings supported the hypothesis that the interaction of polymorphisms of XRCC1-194 Trp/Trp, XRCC1-280 His/His with smoking resulted in the increased risk of lung cancer, and the polymorphisms of XRCC and smoking could play an role in development of lung cancer.

[Preventive effects of modified chitosan medical anti-adhesion membrane on postoperative intra-abdominal adhesion].

OBJECTIVE: To explore the preventive effects of modified chitosan medical anti-adhesion membrane on postoperative intra-abdominal adhesion. METHODS: A total of 86 patients with obstructive colorectal carcinoma undergoing emergent colostomy and second-stage anastomosis were randomly divided into 2 groups (n = 43 each). In the research group modified chitosan medical anti-adhesion membrane were put both at the area of operation and under the incision before abdomen closing, but not so in the control group. The recovery procedures were recorded including gut movement, degree and duration of abdominal pain and cases of adhesive ileus. During the reopening of abdominal cavities 3 to 6 months later, intestinal anastomosis was performed. And adhesive severity was graded blindly and the level of hydroxyproline measured within injured posterior peritoneum and adhesive tissue. RESULTS: As compared with the control, postoperative abdominal pain was weaker; the recovery of gut motor function and eating better ((3.3 ± 1.0) vs (4.2 ± 1.1) days, P < 0.05), the incidence of adhesive ileus lower (1(2.3%) vs 4(9.3%), P < 0.05), adhesion significantly lighter and the hydroxyproline level lower ((0.832 ± 0.071) vs (1.375 ± 0.108) µg/mg protein, P < 0.05) in the research group. CONCLUSION: Modified chitosan medical anti-adhesion membrane has preventive effects on postoperative intra-abdominal adhesion so as to decrease the incidence of adhesive ileus.

Myosin light chain kinase is responsible for high proliferative ability of breast cancer cells via anti-apoptosis involving p38 pathway.

AIM: To investigate whether myosin light chain kinase (MLCK) contributed to the high proliferative ability of breast cancer cells. METHODS: Soft agar colony formation on the MCF-7 and LM-MCF-7 cell lines was determined. The cell cycles of MCF-7 and LM-MCF-7 were detected using flow cytometry analysis. Western blot analysis was performed to detect the expression levels of p-ERK1/2, total-ERK1/2, p-p38, total p38, p-JNK, total-JNK, survivin, Bcl-2, p-MLC, caspase-9, cleaved caspase-9, and MLCK. After treatment with adriamycin (ADR), ML-7 and SB203580, apoptosis was examined using flow cytometry analysis and Annexin V-FITC fluorescence microscopy. RESULTS: The breast cancer LM-MCF-7 cell line with high metastasis potential (a metastitic sub-clone of MCF-7) had higher anti-apoptosis ability relative to MCF-7 cells in response to adriamycin treatment (apoptosis rate: 6.76% vs 28.58%, P<0.05). Moreover, the expression level of MLCK was upregulated and the level of phosphorylated p38 (p-p38) was decreased in LM-MCF-7 cells. Flow cytometry analysis showed that ML-7, selective inhibitor of MLCK, could induce apoptosis of the LM-MCF-7 cells, in which the level of p-p38 was increased. Meanwhile, the expression levels of Bcl-2 and survivin were downregulated, while the caspase-9 was upregulated suggesting that the cells were undergone apoptosis. Flow cytometry analysis showed that SB203580, an inhibitor of p38, abolished ML-7-induced apoptosis, which resulted in the upregulation of Bcl-2 and survivin, and downregulation of caspase-9, suggesting that Bcl-2, survivin and caspase-9 are downstream effectors of p38. CONCLUSION: MLCK is responsible for high proliferative ability of breast cancer cells through anti-apoptosis, in which p38 pathway was involved.

Downregulation of Dickkopf-1 is responsible for high proliferation of breast cancer cells via losing control of Wnt/beta-catenin signaling.

AIM: To investigate the role of DKK-1/Wnt/beta-catenin signaling in high proliferation of LM-MCF-7 breast cancer cells, a sub-clone of MCF-7 cell line. METHODS: Two cell lines (MCF-7 and LM-MCF-7) with different proliferation abilities were used. LM-MCF-7 cells were transiently transfected with the pcDNA3-DKK-1 plasmid encoding the DKK-1 gene (or MCF-7 cells were transfected siRNA targeting DKK-1 mRNA). Flow cytometry analysis and 5-bromo-2'-deoxyuridine (BrdU) incorporation assay were applied to detect the cell proliferation. The expression levels of beta-catenin, phosphorylated beta-catenin, c-Myc, cyclin D1 and Survivin were examined by Western blot analysis. The regulation of Survivin was investigated by Luciferase reporter gene assay. RESULTS: Western blot and RT-PCR analysis showed that the expression level of DKK-1 was downregulated in LM-MCF-7 relative to MCF-7 cells. Flow cytometry and BrdU incorporation assay showed DKK-1 could suppress growth of breast cancer cells. Overexpression of DKK-1 was able to accelerate phosphorylation-dependent degradation of beta-catenin and downregulate the expression of beta-catenin, c-Myc, cyclin D1 and Survivin. Luciferase reporter gene assay demonstrated that Survivin could be regulated by beta-catenin/TCF4 pathway. CONCLUSION: We conclude that the downregulation of DKK-1 is responsible for the high proliferation ability of LM-MCF-7 breast cancer cells via losing control of Wnt/beta-catenin signaling pathway, in which c-Myc, cyclinD1 and Survivin serve as essential downstream effectors. Our finding provides a new insight into the mechanism of breast cancer cell proliferation.

Common variants in human CRC genes as low-risk alleles.

The genetic susceptibility to colorectal cancer (CRC) has been estimated to be around 35% and yet high-penetrance germline mutations found so far explain less than 5% of all cases. Much of the remaining variations could be due to the co-inheritance of multiple low penetrant variants. The identification of all the susceptibility alleles could have public health relevance in the near future. To test the hypothesis that what are considered polymorphisms in human CRC genes could constitute low-risk alleles, we selected eight common SNPs for a pilot association study in 1785 cases and 1722 controls. One SNP, rs3219489:G>C (MUTYH Q324H) seemed to confer an increased risk of rectal cancer in homozygous status (OR=1.52; CI=1.06-2.17). When the analysis was restricted to our 'super-controls', healthy individuals with no family history for cancer, also rs1799977:A>G (MLH1 I219V) was associated with an increased risk in both colon and rectum patients with an odds ratio of 1.28 (CI=1.02-1.60) and 1.34 (CI=1.05-1.72), respectively (under the dominant model); while 2 SNPs, rs1800932:A>G (MSH6 P92P) and rs459552:T>A (APC D1822V) seemed to confer a protective effect. The latter, in particular showed an odds ratio of 0.76 (CI=0.60-0.97) among colon patients and 0.73 (CI=0.56-0.95) among rectal patients. In conclusion, our study suggests that common variants in human CRC genes could constitute low-risk alleles.

Genome-wide linkage scan for colorectal cancer susceptibility genes supports linkage to chromosome 3q.

BACKGROUND: Colorectal cancer is one of the most common causes of cancer-related mortality. The disease is clinically and genetically heterogeneous though a strong hereditary component has been identified. However, only a small proportion of the inherited susceptibility can be ascribed to dominant syndromes, such as Hereditary Non-Polyposis Colorectal Cancer (HNPCC) or Familial Adenomatous Polyposis (FAP). In an attempt to identify novel colorectal cancer predisposing genes, we have performed a genome-wide linkage analysis in 30 Swedish non-FAP/non-HNPCC families with a strong family history of colorectal cancer. METHODS: Statistical analysis was performed using multipoint parametric and nonparametric linkage. RESULTS: Parametric analysis under the assumption of locus homogeneity excluded any common susceptibility regions harbouring a predisposing gene for colorectal cancer. However, several loci on chromosomes 2q, 3q, 6q, and 7q with suggestive linkage were detected in the parametric analysis under the assumption of locus heterogeneity as well as in the nonparametric analysis. Among these loci, the locus on chromosome 3q21.1-q26.2 was the most consistent finding providing positive results in both parametric and nonparametric analyses Heterogeneity LOD score (HLOD) = 1.90, alpha = 0.45, Non-Parametric LOD score (NPL) = 2.1). CONCLUSION: The strongest evidence of linkage was seen for the region on chromosome 3. Interestingly, the same region has recently been reported as the most significant finding in a genome-wide analysis performed with SNP arrays; thus our results independently support the finding on chromosome 3q.

Association of adenomatous polyposis coli (APC) gene polymorphisms with autism spectrum disorder (ASD).

We serendipitously identified a single nucleotide polymorphism (SNP), 8636C>A (rs1804197) in the 3'-untranslated region of the adenomatous polyposis coli (APC) gene to be associated with autism spectrum disorder (ASD). In order to gain further evidence for the association between the APC locus and ASD, we genotyped four additional adjacent common SNPs (rs2229992, rs42427, rs459552, and rs465899) in the coding regions within the APC gene in a set of Swedish ASDs and controls. One common haplotype TGAG was found to be associated with ASD after haplotype analysis using both Haploview v3.1.1 (P = 0.006) and COCAPHASE v2.403 (P = 0.030). This result is the first to suggest that the genomic locus at APC is associated with ASD, and that the APC gene itself is a good predisposing candidate to be evaluated in future studies due to its important role in neuronal development and function.

The estrogen receptor alpha C975G variant in familial and sporadic breast cancer: a case-control study.

BACKGROUND: The estrogen receptor alpha (ESR1) mediates the effect of estrogen in target tissues. Estrogen is important in breast cancer development and several polymorphic variants in the ESR1 gene have been investigated for association with breast cancer. The C975G variant is the most extensively studied and has been suggested to be a risk factor. MATERIALS AND METHODS: The frequency of the C975G variant was investigated in 288 sporadic, 197 low-risk non-BRCA1/2 familial and 191 high-risk non-BRCA1/2 familial breast cancer cases and 653 controls. RESULTS: There was a lower frequency of the C975G variant in high-risk familial breast cancer cases compared to the controls (18% versus 22%, p=0.046). The odds ratio (OR) for the GG homozygotes was 0.2 (95% CI: 0.06-0.8) compared to the CC homozygotes. No association was seen with sporadic or low-risk familial breast cancer. CONCLUSION: The results of this study indicated that the common C975G variant may have an effect on familial breast cancer susceptibility.

Colorectal cancer as a complex disease: defining at-risk subjects in the general population - a preventive strategy.

Over the last few decades it has become clear that highly penetrant disease genes are responsible for a minor proportion of colorectal cancer cases. Families with hereditary syndromes are today recognized and included in surveillance programs known to reduce morbidity and mortality in colorectal cancer. Colorectal cancer is preventable and screening strategies in whole populations are currently under debate. Colorectal cancer can be considered a complex disease, with a combination of predisposing genetic variants and environmental factors that contribute to the illness as a whole. The progress made in the genome project provides an opportunity to determine such genetic variants and environmental factors. This knowledge can be used to define a subpopulation at increased risk for colorectal cancer. It will be more feasible to design preventive strategies for this subgroup than for a whole population.

Definition of candidate low risk APC alleles in a Swedish population.

Many families experience an apparently inherited increased risk of colorectal cancer (CRC) similar to the known syndromes familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). Besides these high-risk syndromes, approximately 10% of all CRC cases come from families with 2 affected 1st-degree relatives, and even 1st-degree relatives to a single case of CRC are at increased risk. Risk subjects from these families frequently show polyps at colonoscopy, which suggests the APC gene as a good candidate susceptibility gene for these attenuated polypotic syndromes. We used the sensitive DHPLC technique to search for possible predisposing germline mutations in the entire APC gene in 91 risk subjects from these high- and low-risk syndromes with unknown predisposing genes. Most exons were also screened for mutations in 96 normal controls and 96 colorectal cancer cases. In our study we probably have identified the most common APC variants in a Swedish population. Among 30 germline variants identified, 1 clearly pathogenic nonsense mutation and 11 putative pathogenic variants (10 missense and one 3' UTR) were found in 20 index patients (22%). Twelve silent as well as 5 intronic variants were considered nonpathogenic. Two of the missense variants found here, E1317Q and D1822V, have previously been related to a difference in risk of colorectal cancer. One variant, 8636C>A, located within the 3' UTR region of the APC gene, was suggested to constitute an additional low risk allele with a similar relative risk as the Jewish I1307K mutation (OR = 1.8; 95% CI, 0.96-3.40). The question of whether all the other variants confer an increased colorectal cancer risk warrants future large association studies.

A screen for germline mutations in the gene encoding CCCTC-binding factor (CTCF) in familial non-BRCA1/BRCA2 breast cancer.

INTRODUCTION: The CCCTC-binding factor (CTCF), known as a versatile transcription factor and chromatin insulator and to be involved in X inactivation, has also been suggested to be a tumour suppressor on 16q. We investigated 153 patients with familial non-BRCA1/BRCA2 breast cancer for germline mutations in the CTCF gene. METHODS: Mutation screening of CTCF was performed by denaturing high-performance liquid chromatography followed by cycle sequencing. RESULTS: We found two sequence variants, 240G-->A in the 5' untranslated region and 1455C-->T (S388S) in exon 4, in five familial breast cancer cases. Three of these five cases had both variants. Cases and controls showed the same prevalence for the two variants, which were found in linkage disequilibrium in most cases and controls. CONCLUSION: The present study suggests that germline mutations in CTCF are not important as a risk factor for breast cancer.

The role of hMLH3 in familial colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is commonly associated with at least three currently known DNA mismatch repair genes: (a) hMSH2; (b) hMLH1; and (c) hMSH6. A majority of HNPCC families has identifiable mutations in hMLH1 and hMSH2. When these mutations cause an inherited risk of colorectal cancer, they are also most often associated with microsatellite instability in the tumors. Recently, hMLH3 was suggested to be causative in HNPCC. We screened 70 index patients suggestive of a genetic predisposition for germ-line mutations in hMLH3 with denaturing high-performance liquid chromatography. One frameshift mutation and 11 missense mutations were identified in 16 index patients (23%). Most families presented evidence against hMLH3 as a high risk factor in familial colorectal cancer, and most of the mutations were found in the low risk patients, suggesting hMLH3 to be a low risk gene for colorectal cancer. We demonstrate in one family that a hMLH3 mutation segregated with disease together with a missense mutation in hMSH2, which makes us hypothesize that these mutations work together in an additive manner and result in an elevated risk of colorectal tumors in the family. None of the tumors with hMLH3 mutations showed microsatellite instability, which demonstrates that hMLH3 does not make its contribution to carcinogenesis through an impaired DNA mismatch repair function.