Diagnostic Performance of Intestinal Fusobacterium nucleatum in Colorectal Cancer: A Meta-Analysis

Background:

Increasing evidence has supported the link of intestinal Fusobacterium nucleatum infection to colorectal cancer (CRC). However, the value of F. nucleatum as a biomarker in CRC detection has not been fully defined. In order to reduce the random error and bias of individual research, this meta-analysis aimed to evaluate the diagnostic performance of intestinal F. nucleatum in CRC patients and provide evidence-based data to clinical practice.

Methods:

An article search was performed from PubMed, Embase, Cochrane Library, and Web of Science databases up to December 2017, using the following key words: “Fusobacterium nucleatum”, ”Fusobacterium spp.”, ”Fn”, “colorectal cancer(s)”, “colorectal carcinoma(s)”, “colorectal neoplasm(s)”, and “colorectal tumor(s)”. Articles on relationships between F. nucleatum and CRC were selected according to the preestablished inclusion and exclusion criteria. This meta-analysis was performed using STATA 12.0 software, which included mapping of forest plots, heterogeneity tests, meta-regression, subgroup analysis, sensitivity analysis, and publication bias. The sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and their corresponding 95% confidence interval (CI) of each eligible study were summarized.

Results:

Finally, data for 1198 participants (629 CRC and 569 healthy controls) in 10 controlled studies from seven articles were included. The summary receiver operator characteristic curve was mapped. The diagnostic performance of intestinal F. nucleatum infection on CRC was as follows: the area under the curve: 0.86 (95% CI: 0.83–0.89), the pooled sensitivity: 0.81 (95% CI: 0.64–0.91), specificity: 0.77 (95% CI: 0.59–0.89), and DOR: 14.00 (95% CI: 9.00–22.00).

Conclusion:

Intestinal F. nucleatum is a valuable marker for CRC diagnosis.

Association of Fusobacterium nucleatum infection with colorectal cancer in Chinese patients

AIM: To investigate Fusobacterium nucleatum (F. nucleatum) abundance in colorectal cancer (CRC) tissues and its association with CRC invasiveness in Chinese patients.

METHODS: The resected cancer and adjacent normal tissues (10 cm beyond cancer margins) from 101 consecutive patients with CRC were collected. Fluorescent quantitative polymerase chain reaction (FQ-PCR) was applied to detect F. nucleatum in CRC and normal tissues. The difference of F. nucleatum abundance between cancer and normal tissues and the relationship of F. nucleatum abundance with clinical variables were evaluated. Fluorescence in situ hybridization (FISH) analysis was performed on 22 CRC tissues with the highest F. nucleatum abundance by FQ-PCR testing to confirm FQ-PCR results.

RESULTS: The median abundance of F. nucleatum in CRC tissues [0.242 (0.178-0.276)] was significantly higher than that in normal controls [0.050 (0.023-0.067)] (P < 0.001). F. nucleatum was over-represented in 88/101 (87.1%) CRC samples. The abundance of F. nucleatum determined by 2^-ΔCT was significantly greater in tumor samples [0.242 (0.178, 0.276)] than in normal controls [0.050 (0.023, 0.067)] (P < 0.001). The frequency of patients with lymph node metastases was higher in the over-abundance group [52/88 (59.1%)] than in the under-abundance group [0/13 (0%)] (P < 0.005). No significant association of F. nucleatum with other clinico-pathological variables was observed (P > 0.05). FISH analysis also found more F. nucleatum in CRC than in normal tissues (median number 6, 25^th 3, 75^th 10 vs 2, 25^th 1, 75^th 5) (P < 0.01).

CONCLUSION: F. nucleatum was enriched in CRC tissues and associated with CRC development and metastasis.

The effect of miRNA-122 in regulating fat deposition in a cell line model

Accumulating evidence supports the role of miR-122 in fatty liver disease. We investigated miR-122 expression in a steatotic hepatocyte model, the effect of miR-122 over-expression and inhibition in the pathogenesis. Human hepatic cell line L02 was induced with oleic acid to establish the steatotic hepatocyte model. Intracellular lipid content was observed with laser scanning confocal microscope (LSCM), and triglyceride content was determined with kits. Total RNA was extracted and reversely transcribed into cDNA. miR-122 expression was measured using qRT-PCR. Subsequently, miR-122 mimic and miR-122 inhibitor were transfected into steatotic hepatocytes to observe their effect on intracellular lipid content. The lipid fluorescence intensity and triglyceride content within the steatotic hepatocytes were significantly higher than those in normal control (860.01 ± 26.52 vs. 257.77 ± 29.69 and 3.47 ± 0.12 vs. 1.85 ± 0.02 at 24 h) (P < 0.01). miR-122 expression in steatotic hepatocytes was down-regulated compared with that in control (2-ΔCt value: 0.0286 ± 0.0078 vs. 0.0075 ± 0.0012) (P ≪ 0.01). After transfection, miR-122 expression (2-ΔCt value) in the miR-122 mimic group increased 2.96-fold compared with that in control, and its lipid fluorescence intensity was significantly lower than that in control (790.92 ± 46.72 vs. 1,022.16 ± 49.66) (P < 0.01). Nevertheless, miR-122 expression decreased 3.45-fold in the miR-122 inhibitor group compared with that in control, and its fluorescence intensity was significantly higher than that in control (1,386.49 ± 40.34 vs 1,022.16 ± 49.66)(P ≪ 0.01). We concluded that miR-122 was down-regulated in steatotic hepatocytes model. The pathogenesis of hepatocyte steatosis was enhanced by miR-122 mimic and reduced with miR-122 inhibitor.

Genetic and epigenetic variants influencing the development of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is common worldwide. The importance of genetic and epigenetic changes in etiology and pathogenesis of NAFLD has been increasingly recognized. However, the exact mechanism is largely unknown. A large number of single nucleotide polymorphisms (SNPs) related to NAFLD has been documented by candidate gene studies (CGSs). Among these genes, peroxisome proliferatoractivated receptor-γ, adiponectin, leptin and tumor necrosis factor-α were frequently reported. Since the introduction of genome-wide association studies (GWASs), there have been significant advances in our understanding of genomic variations of NAFLD. Patatin-like phospholipase domain containing family member A3 (PNPLA3, SNP rs738409, encoding I148M), also termed adiponutrin, has caught most attention. The evidence that PNPLA3 is associated with increased hepatic fat levels and hepatic inflammation has been validated by a series of studies. Epigenetic modification refers to phenotypic changes caused by an adaptive mechanism unrelated to alteration of primary DNA sequences. Epigenetic regulation mainly includes microRNAs (miRs), DNA methylation, histone modifications and ubiquitination, among which miRs are studied most extensively. miRs are small natural single stranded RNA molecules regulating mRNA degradation or translation inhibition, subsequently altering protein expression of target genes. The miR-122, a highly abundant miR accounting for nearly 70% of all miRs in the liver, is significantly under-expressed in NAFLD subjects. Inhibition of miR-122 with an antisense oligonucleotide results in decreased mRNA expression of lipogenic genes and improvement of liver steatosis. The investigation into epigenetic involvement in NAFLD pathogenesis is just at the beginning and needs to be refined. This review summarizes the roles of genetics and epigenetics in the development of NAFLD. The progress made in this field may provide novel diagnostic biomarkers and therapeutic targets for NAFLD management.

Natural course of nonalcoholic fatty liver disease in southern China: a prospective cohort study

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease, the natural course of which has not been well documented. This study aimed to perform a prospective cohort study to investigate NAFLD in a Chinese population.

METHODS

Using our previous epidemiological survey, 3543 patients were followed-up for a median of 4 years (range 3.6-4.8 years). Of these patients, 624 participated in a new survey. Interviews, physical examinations, biochemical tests and abdominal ultrasonography were repeated for these patient.

RESULTS

The annual incidence of NAFLD was 9.1% (male 7.3% vs female 9.7%, P=0.047). Among 117 NAFLD patients at baseline, 51 (43.6%) remained unchanged, 26 (22.2%) became worse, and 40 (34.2%) improved. Patients with simultaneous metabolic syndrome (MS) showed accelerated progression (P=0.026). For the NAFLD patients, both general annual mortality rates and cardiovascular disease deaths (both 0.54%) were significantly higher than those of patients without NAFLD (0.19% and 0.17%, P=0.005). Age and several variables related to MS were risk factors for NAFLD progression.

CONCLUSIONS

The incidence of NAFLD in southern China is relatively lower in comparison with that of the developed countries. Patients with NAFLD have a benign prognosis. Variables related to MS are risk factors for NAFLD occurrence and progression.

Influence of polygenetic polymorphisms on the susceptibility to non-alcoholic fatty liver disease of Chinese people

BACKGROUND AND AIM

The aim of this study was to investigate the influence of polygenetic polymorphisms, which play a role in the pathogenesis of metabolic syndrome, on the susceptibility to non-alcoholic fatty liver disease (NAFLD) of Chinese people.

METHODS

The subjects were selected from an epidemiological survey in the Guangdong province of southern China. In each polymorphism study, 50-117 subjects who met the diagnostic criteria of NAFLD and had typical clinical and ultrasonographic findings were placed into the case group. Using a nested case-control design, the same numbers of matched people without NAFLD were included as controls. Single nucleotide polymorphisms (SNP) at nine positions in seven candidate genes were tested. These SNP were found to be associated with the pathogenesis of metabolic syndrome. Genetic analyses were performed using genomic DNA extracted from peripheral blood leukocytes. Polymerase chain reaction-restriction fragment length polymorphism was applied to detect SNP.

RESULTS

Most candidate genes' SNP were associated with susceptibility to NAFLD. Some showed positive relationships (increased risk): tumor necrosis factor-alpha-238, adiponectin-45, leptin-2548, peroxisome proliferator-activated receptors-161 and phosphatidyletha-nolamine N-methyltransferase-175. Other SNP demonstrated a negative association (decreased risk): adiponectin-276 and hepatic lipase-514. Only two were not associated: tumor necrosis factor-alpha-380 and peroxisome proliferator-activated receptors-gamma co-activator-1alpha-482.

CONCLUSION

Most candidate genes' SNP examined in metabolic syndrome patients were associated with susceptibility to NAFLD.

Effect of peroxisome proliferator-activated receptors-gamma and co-activator-1alpha genetic polymorphisms on plasma adiponectin levels and susceptibility of non-alcoholic fatty liver disease in Chinese people

BACKGROUND/AIMS

Peroxisome proliferator-activated receptors-gamma (PPAR-gamma) and its co-activator-1alpha (PGC-1alpha) are involved in the regulation of lipid and glucose metabolisms. This study aimed to investigate the genetic polymorphisms of PPAR-gamma and PGC-1alpha in Chinese people and their influence on plasma adiponectin levels and non-alcoholic fatty liver disease (NAFLD) susceptibility.

METHODS

Ninety-six patients with NAFLD and 96 healthy controls were included. The single nucleotide polymorphisms (SNPs) of C161T PPAR-gammaand Gly482Ser PGC-1alpha genes were analysed by polymerase chain reaction and restriction fragment length polymorphism.

RESULT

The CC, CT and TT genotypic distributions of the NAFLD group were significantly different from those of controls (55.2, 39.6, 5.2 vs. 74.0, 25.0, 1.0%; P=0.015). The allelic frequencies of C and T were also different between the two groups (P=0.004). As for the PGC-1alpha gene, there was no difference of the genotypic and allelic frequencies between the two groups (P>0.05). In NAFLD patients, the plasma adiponectin concentrations were lower in the PPAR-gamma CT/TT genotypes compared with those in the CC genotype group (3.0+/-0.6 vs. 4.3+/-0.9, P=0.02). Multivariate logistic regression analysis showed that CT/TT genotypes of PPAR-gamma, TG, waist hip ratio, hypoadiponectinaemia and homoeostasis model assessment (HOMA)-IR were the risk factors for NAFLD.

CONCLUSION

SNPs in the PPAR-gamma, but not PGC-1alpha, gene are associated with NAFLD susceptibility possibly through the adiponectin pathway.

Prevalence of fatty liver disease and its risk factors in the population of South China

AIM: To investigate the population-based prevalence of fatty liver disease (FLD) and its risk factors in Guangdong Province, China.

METHODS: A cross-sectional survey with multiple-stage stratified cluster and random sampling of inhabitants over 7-year-old was performed in 6 urban and rural areas of Guangdong Province, China. Questionnaires, designed by co-working of epidemiologists and hepatologists, included demographic characteristics, current medication use, medical history and health-relevant behaviors, i.e., alcohol consumption, smoking habits, dietary habits and physical activities. Anthropometric measurements, biochemical tests and abdominal ultrasonography were carried out.

RESULTS: Among the 3543 subjects, 609 (17.2%) were diagnosed having FLD (18.0% males, 16.7% females, P > 0.05). Among them, the prevalence of confirmed alcoholic liver disease (ALD), suspected ALD and nonalcoholic fatty liver disease (NAFLD) were 0.4%, 1.8%, and 15.0%, respectively. The prevalence rate (23.0%) was significantly higher in urban areas than (12.9%) in rural areas. After adjustment for age, gender and residency, the standardized prevalence of FLD in adults was 14.5%. Among them, confirmed ALD, suspected ALD and NAFLD were 0.5%, 2.3%, and 11.7%, respectively, in adults and 1.3% (all NAFLD) in children at the age of 7-18 years. The overall prevalence of FLD increased with age in both genders to the peak of 27.4% in the group of subjects at the age of 60-70 years. The prevalence rate was significantly higher in men than in women under the age of 50 years (22.4% vs 7.1%, P < 0.001). However, the opposite phenomenon was found over the age of 50 years (20.6% vs 27.6%, P < 0.05). Multivariate and logistic regression analysis indicated that male gender, urban residency, low education, high blood pressure, body mass index, waist circumference, waist to hip ratio, serum triglyceride and glucose levels were the risk factors for FLD.

CONCLUSION: FLD, especially NAFLD, is prevalent in South China. There are many risk factors for FLD.

Short and long term efficacy of high intensity focused ultrasound therapy for advanced hepatocellular carcinoma

BACKGROUND

The aim of this study was to investigate the short and long term efficacy of high intensity focused ultrasound therapy (HIFU) in patients with advanced hepatocellular carcinoma (HCC).

METHODS

Patients with surgically unresectable HCC received either HIFU plus supportive treatment (HIFU group, n = 151) or supportive treatment only (control group, n = 30), according to their willingness. Short term efficacy, including improvement in tumor imaging parameters, decrease in serum alpha-fetoprotein (AFP) levels, symptom relief (i.e. Karnofsky Performance Status and numerical rating scales) and response rates, and long term efficacy, including an increase in survival rates and improvement of quality of life (QOL), was monitored.

RESULTS

Tumor imaging parameters, serum AFP levels and symptom scores improved significantly in the HIFU group compared with the control group (all P < 0.05). In the HIFU group, a complete and a partial response were achieved in 28.5% (n = 43) and 60.3% (n = 91) of cases, respectively, while the rates were 0% and 16.7% (n = 5), respectively, in the control group. The overall response rate (88.8%) was significantly greater in the HIFU group (16.7%) than in the control group (P < 0.01). In addition, the 1- and 2-year survival rates were 50.0% and 30.9%, respectively, in the HIFU group, which were significantly greater than those (3.4% and 0%, respectively) in the control group (both P < 0.01). The QOL score was 83.1 +/- 8.0 at 3 months after HIFU, which was significantly greater than the pre-HIFU score (67.7 +/- 5.9) and the score at 3 months after treatment (69.0 +/- 8.5) in the control group (both P < 0.05). No severe complications occurred during and after HIFU.

CONCLUSION

HIFU is an effective and safe ablation therapy with satisfactory short and long term efficacy for patients with advanced HCC.

[Serotonin transporter gene polymorphisms in irritable bowel syndrome and their impact on tegaserod treatment]

OBJECTIVE

To investigate the serotonin reuptake transporter (SERT) genetic polymorphisms in the 5-hydroxytryptamine (5-HT) transporter gene-linked polymorphic region (5-HTTLPR) and the variable number tandem repeats (VNTRs) in intron 2 among Chinese people, and their relationship to the pathogenesis of irritable bowel syndrome (IBS); and to investigate the impact of SERT genotypes on the efficacy of 5-HT(4) receptor agonist tegaserod in constipation predominant type (C-IBS) patients.

METHODS

PCR was used to detect the genetic polymorphisms in 87 patients with IBS confirmed with Rome II criteria and 96 healthy subjects, then 41 C-IBS patients received tegaserod 6 mg twice daily for 4 weeks. Each patient recorded his or her symptoms in a diary. Efficacy was assessed by patient's experience of overall symptoms and severity of constipation before and after the treatment.

RESULTS

The 5-HTTLPR genotypes frequencies were: S/S 52.9%, S/L 31.0%, L/L 16.1% in IBS patients; and S/S 57.3%, S/L 35.4%, L/L 7.3% in control. VNTRs genotypes were STin2.10/10: 2.3%, STin2.12/10: 17.2%, STin2.12/12: 80.5% in IBS patients; and STin2.10/10: 2.1%, STin2.12/10: 11.4%, STin2.12/12: 86.5% in control. There was no significant difference in the two genotypes frequencies between IBS and control groups (P > 0.05). However, the allele frequency of the L/L genotype was significantly higher in the C-IBS group than in control (25.0% vs 7.3%, P < 0.05). The clinical responder rates of tegaserod in S/S (85.0%) and S/L (70.0%) genotypes differed significantly from that (36.4%) in L/L genotype (P < 0.05). The scores of Subject's Global Assessment of relief after treatment were: S/S 1.35 +/- 0.81, S/L 1.70 +/- 0.95 vs L/L 2.27 +/- 0.45 (P < 0.05). All other variables for assessment of efficacy including stool frequency, stool consistency and sensation of bowel complete evacuation in L/L genotype were also significantly poorer than those in S/S and S/L (P < 0.05).

CONCLUSIONS

5-HTTLPR and VNTRs genetic polymorphisms existed in Chinese people. In general, the genotypes were not involved in the pathogenesis of IBS. However people with L/L genotype were vulnerable for development of C-IBS. The 5-HTTLPR genetic polymorphisms influenced the efficacy of tegaserod treatment in C-IBS patients with L/L being poorer than S/S and S/L genotypes.