Single nucleotide polymorphism in the promoter region of human alpha-fetoprotein (AFP) gene and its significance in hepatocellular carcinoma (HCC)

A comparison of clinical pathologic characteristics between alpha-fetoprotein negative and positive hepatocellular carcinoma patients from Eastern and Southern China

Background

Alpha-fetoprotein (AFP) is a biomarker used in clinical management of hepatocellular carcinoma (HCC), however, approximately 40% of HCC patients do not present with elevated serum AFP levels. This study aimed to investigate the clinical and pathologic characteristics between AFP positive and negative HCC patients to allow for improved clinical management and prognostication of the disease.

Methods

This study observed a cohort of HCC patients from Eastern and Southern China with comparisons of the clinical and pathologic features between serum AFP positive and negative patient groups; patients with decompensated hepatic cirrhosis, those with chronic hepatitis B, and hepatitis B virus (HBV) asymptomatic carrier patients were used as controls. Data included the laboratory results, pathology diagnosis, clinical staging and scores were obtained from routine clinical diagnostic methods.

Results

Patients with HCC, larger tumor sizes, liver cancer with hepatic cirrhosis, portal vein thrombosis, metastasis, high Child–Pugh score, high Barcelona-Clínic Liver Cancer (BCLC) stage, and advanced clinical stage had significantly higher serum AFP levels. Also, patients with HBsAg and HBeAg positive, high HBV DNA levels had significantly higher serum AFP levels. Patients with high serum AFP levels had higher protein induced by vitamin K absence or antagonist-II (PIVKA-II), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alpha-l-fucosidase (AFU), gamma-glutamyl transpeptidase (γ-GT), γ-GT /ALT, direct bilirubin (DBIL), indirect bilirubin (IDBIL), fibrinogen, and D-dimer levels. Patients with AFP positive had higher white blood cells (WBC), neutrophil, monocyte, and platelet count and neutrophil to lymphocyte ratio (NLR).

Conclusions

The are significant differences in clinical pathologic characteristics between AFP positive and negative HCC patients which may be helpful for the management and prognostication of the disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02279-w.

Mechanisms by Which Probiotic Bacteria Attenuate the Risk of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and the second leading cause of cancer-related deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV), alcoholic liver disease (ALD), and non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) are the major extrinsic risk factors of HCC development. Genetic background is pivotal in HCC pathogenesis, and both germline mutations and single nucleotide polymorphism (SNP) are intrinsic risk factors of HCC. These HCC risk factors predispose to hepatic injury and subsequent activation of fibrogenesis that progresses into cirrhosis and HCC. Probiotic bacteria can mitigate HCC risk by modulating host gut microbiota (GM) to promote growth of beneficial microbes and inhibit HCC-associated dysbiosis, thus preventing pathogen-associated molecular patterns (PAMPs)-mediated hepatic inflammation. Probiotics have antiviral activities against HBV and HCV infections, ameliorate obesity and risk of NAFLD/NASH, and their antioxidant, anti-proliferative, anti-angiogenic, and anti-metastatic effects can prevent the HCC pathogenesis. Probiotics also upregulate the expression of tumor suppressor genes and downregulate oncogene expression. Moreover, metabolites generated by probiotics through degradation of dietary phytochemicals may mitigate the risk of HCC development. These multiple anticancer mechanisms illustrate the potential of probiotics as an adjuvant strategy for HCC risk management and treatment.

Targeted Diphtheria Toxin-Based Therapy: A Review Article

Cancer remains one of the leading causes of death worldwide. Conventional therapeutic strategies usually offer limited specificity, resulting in severe side effects and toxicity to normal tissues. Targeted cancer therapy, on the other hand, can improve the therapeutic potential of anti-cancer agents and decrease unwanted side effects. Targeted applications of cytolethal bacterial toxins have been found to be especially useful for the specific eradication of cancer cells. Targeting is either mediated by peptides or by protein-targeting moieties, such as antibodies, antibody fragments, cell-penetrating peptides (CPPs), growth factors, or cytokines. Together with a toxin domain, these molecules are more commonly referred to as immunotoxins. Targeting can also be achieved through gene delivery and cell-specific expression of a toxin. Of the available cytolethal toxins, diphtheria toxin (DT) is one of the most frequently used for these strategies. Of the many DT-based therapeutic strategies investigated to date, two immunotoxins, Ontak^TM and Tagraxofusp^TM, have gained FDA approval for clinical application. Despite some success with immunotoxins, suicide-gene therapy strategies, whereby controlled tumor-specific expression of DT is used for the eradication of malignant cells, are gaining prominence. The first part of this review focuses on DT-based immunotoxins, and it then discusses recent developments in tumor-specific expression of DT.

The role of ERCC1 and AFP gene polymorphism in hepatocellular carcinoma

The aim of this study was to evaluate the effects of polymorphisms in excision repair cross-complementation group 1 (ERCC1) and alpha-fetoprotein (AFP) genes and their haplotypes on the susceptibility to hepatocellular carcinoma (HCC), and to decipher the association between single-nucleotide polymorphisms (SNPs) and clinicopathologic characteristics of HCC.Peripheral blood DNA was extracted from 206 subjects. SNaPshot technique was used for genotyping 5 SNP sites of the ERCC1 rs735482, rs1046282, rs3212948, and AFP rs737241, rs4024 genotypes. Chi-squared test and logistic regression model were used to analyze the relationship of different genotypes or haplotype and the susceptibility and clinicopathologic characteristics of HCC.The frequency of GG.GA and AA genotypes at the AFP rs737241 site in the case and control groups showed statistically significant differences (P < .05). The risk of HCC in subjects carrying mutated allele A (GA+AA) was increased by 0.543-times (P < .05) compared to that in the subjects with the GG genotype. Significant differences were observed in the linkage disequilibrium between 2 of the five SNPs (P < .05); the frequency of ERCC1 C-C and AFP A-A haplotypes was significantly lower in the case group than in the control group (P < .05). The results of clinicopathologic analysis showed that A allele at the rs737241 locus could increase the expression level of AFP (P = .007), the rs1046282 mutation C allele could increase the AFP expression level (P = .011), rs4024 locus mutation A allele could reduce the risk of vascular invasion (P = .013), rs3212948 locus mutation T allele could reduce the differentiation of liver cancer (P = .022), rs1046282 locus C allele could reduce the DNA load of hepatitis B virus (P = .035), and rs735482 A allele could increase the tumor size in HCC (P = .037).The SNPs in rs737241 for AFP gene may correlate with the occurrence of HCC. The SNPs in ERCC1 and AFP genes may affect the prognosis of HCC, offering reliable information for early prediction of tumor progression and diagnosis of HCC.

Genetic correction of serum AFP level improves risk prediction of primary hepatocellular carcinoma in the Dongfeng-Tongji cohort study

Serum alpha-fetoprotein (AFP) is the most commonly used tumor biomarker for screening and diagnosis of primary hepatocellular carcinoma (HCC). However, the predictive effect for HCC risk is still unsatisfactory. The aim of this prospective study was to estimate whether the individual genetic correction could improve the prediction efficiency of AFP for HCC risk. A prospective analysis with 9819 baseline HCC-free individuals based on a large population-based Chinese cohort study was performed. Two single-nucleotide polymorphisms (SNPs) associated with serum AFP level were used to calculate the genetic corrected AFP level (rs12506899 and rs2251844). Statistical analysis including logistic regression analysis and the area under the receiver operating characteristic (ROC) curve were used to assess the discriminative ability of the original and genetic corrected AFP level for HCC risk. The odds ratios (ORs) and 95% confidence intervals (95% CIs) were presented. Fifty-seven participants were diagnosed with HCC for the first time. After adjusting AFP level with genetic effects, the participants for HCC risk increased compared to those with AFP level alone (OR = 5.34, 95% CI = 2.57-11.13; P < 0.001 vs. OR = 5.04, 95% CI = 2.46-10.30; P < 0.001). In addition, the area under the curve (AUC) for the discrimination of HCC elevated from 0.611 to 0.726. The efficiency in HCC prediction using serum AFP level can be improved by adjusting AFP level based on genetic effects. The genetic correction effect on serum AFP should be considered in the clinic application of such tumor biomarkers.

Transcriptome sequencing identified hub genes for hepatocellular carcinoma by weighted-gene co-expression analysis

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, and it remains a challenge to understand the genetic mechanisms underlying hepatocarcinogenesis. A global gene network of differential expression profiles in HCC has yet to be fully characterized. In the present study, we performed transcriptome sequencing (mRNA and lncRNA) in liver cancer and cirrhotic tissues of nine HCC patients. We identified differentially expressed genes (DEGs) and constructed a weighted gene co-expression network for the DEGs. In total, 755 DEGs (747 mRNA and eight lncRNA) were identified, and several co-expression modules were significantly associated with HCC clinical traits, including tumor location, tumor grade, and the α-fetoprotein (AFP) level. Of note, we identified 15 hub genes in the module associated with AFP level, and three (SPX, AFP and ADGRE1) of four hub genes were validated in an independent HCC cohort (n=78). Identification of hub genes for HCC clinical traits has implications for further understanding of the molecular genetic basis of HCC.

Persistent α-Fetoprotein Elevation in Healthy Adults and Mutational Analysis of α-Fetoprotein Promoter, Enhancer, and Silencer Regions

Background/Aims

α-Fetoprotein (AFP) is normally <10 ng/mL in adults without malignancy or liver regeneration. However, hereditary or nonhereditary persistence of AFP in healthy adults may be encountered in clinical practice. This study describes four cases of persistent AFP elevation in healthy adults and investigates mutations in key transcription regulatory regions of the AFP gene as potential drivers of AFP overexpression.

Methods

Four healthy adults with persistently elevated AFP levels (12.1 to 186.1 ng/mL) for >1 year, and 20 controls with low AFP levels (<0.61 to 2.9 ng/mL) were included in the study. AFP levels were collected from the families of two of the patients. We sequenced five regions that are critical for AFP expression: a promoter, two enhancers, and two silencers.

Results

One of the two cases in which family information was represented is the first case of hereditary persistence of AFP in South Korea. Mutations related to AFP overexpression were not found in the transcription regulatory regions among the four patients.

Conclusions

Persistent AFP elevation is a heterogeneous condition with or without a hereditary pattern and may be caused by factors outside of transcription regulatory region changes. Further research on the mechanism of AFP elevation is needed.

SOCS3 Genetic Polymorphism Is Associated With Clinical Features and Prognosis of Hepatocellular Carcinoma Patients Receiving Hepatectomy

Previous studies showed that suppressor of cytokine signaling 3 (SOCS3) protein is associated with incidence and progression of hepatocellular carcinoma (HCC); however, the association between the genetic polymorphism of SOCS3 gene and HCC remains unknown. A total of 254 HCC patients and 354 healthy controls were enrolled. All HCC patients underwent partial hepatectomy as initial treatment and were followed. Three SOCS3 gene polymorphisms, namely, rs4969170 A>G, rs8064821 C>T, and rs12953258 C>A were determined. Our data show that the rs4969170 A>G polymorphism dramatically affects the susceptibility to HCC in our cohorts. Logistic regression analyses revealed that the rs4969170 GG is a risk factor for HCC after the adjustment with confounding factors. The rs4969170A>G polymorphism is also associated with the clinical features of HCC patients and predicts the postoperative relapse-free survival and overall survival. The rs4969170GG genotype carrier had a worse prognosis than the rs4969170AG and rs4969170AA carrier. Our findings suggest that the rs4969170A>G polymorphism of SOCS3 gene may be used as a prognostic predictor for HCC patients who underwent surgical treatment.

Therapeutic efficacy of improved α-fetoprotein promoter-mediated tBid delivered by folate-PEI600-cyclodextrin nanopolymer vector in hepatocellular carcinoma

SNPs in human AFP promoter are associated with serum AFP levels in hepatocellular carcinoma (HCC), suggesting that AFP promoter variants may generate better transcriptional activities while retaining high specificity to AFP-producing cells. We sequenced human AFP promoters, cloned 15 different genotype promoters and tested their reporter activities in AFP-producing and non-producing cells. Among various AFP variant fragments tested, EA4D exhibited the highest reporter activity and thus was selected for the further study. EA4D was fused with tBid and coupled with nano-particle vector (H1) to form pGL3-EA4D-tBid/H1. pGL3-EA4D-tBid/H1 could express a high level of tBid while retain the specificity to AFP-producing cells. In a HCC tumor model, application of pGL3-EA4D-tBid/H1 significantly inhibited the growth of AFP-producing-implanted tumors with minimal side-effects, but had no effect on non-AFP-producing tumors. Furthermore, pGL3-EA4D-tBid/H1 could significantly sensitize HCC cells to sorafenib, an approved anti-HCC agent. Collectively, pGL3-EA4D-tBid/H1, a construct with the AFP promoter EA4D and the novel H1 delivery system, can specifically target and effectively suppress the AFP-producing HCC. This new therapeutic tool shows little toxicity in vitro and in vivo and it should thus be safe for further clinical tests.

Association of CHKA polymorphism (rs3794186) with α-fetoprotein levels in hepatocellular carcinoma

Choline kinase α (CHKA) has been identified to be associated with cancer development and progression. In this study, we investigated whether exonic single nucleotide polymorphisms (SNPs) of the CHKA gene are associated with hepatocellular carcinoma (HCC). Among all SNPs in the 3'-untranslated region (UTR), 5'-UTR and the coding region of CHA, only two SNPs (rs3794186 and rs11481) in the 3'-UTR had a heterozygosity above 0.1 and a minor allele frequency above 0.1. Therefore, we selected and assessed these two SNPs (rs3794186 and rs11481) in 189 HCC patients and 194 controls. Genetic data were analyzed using the SNPAnalyzer Pro, SNPStats and Haploview programs. No SNPs of the CHKA gene were found to be associated with the risk of HCC development. Upon analysis of the clinical characteristics of HCC, the genotypic frequency of rs3794186 was significantly associated with serum α-fetoprotein (AFP) levels (P=0.022 in the co-dominant 1 model, P=0.0045 in the dominant model and P=0.0052 in the log-additive model). A significant difference in the allelic frequency of rs3794186 was also observed between the high AFP (>200 ng/ml) group and the low AFP (≤200 ng/ml) group [P=0.009, odds ratio (OR) = 0.33, 95% confidence interval (95% CI) = 0.14-0.75]. The T allele frequency of rs3794186 was lower in the high AFP group (6.6%) compared to that in the low AFP group (17.8%). Our results suggest that CHKA SNPs (rs3794186 and rs11481) are not associated with HCC development; however, rs3794186 may correlate with serum AFP levels in HCC.

A 40-bp insertion/deletion polymorphism in the constitutive promoter of MDM2 confers risk for hepatocellular carcinoma in a Chinese population

The pathogenesis of HCC is a multistage process with the involvement of genetic factors. The aim of the present study is to investigate the possible association between a 40-bp insertion/deletion polymorphism (indel) at constitutive promoter of MDM2 and risk of hepatocellular carcinoma (HCC) in a Chinese population. Using 420 HCC patients and 423 control subjects, we genotyped the indel polymorphism (rs3730485) using polymerase chain reaction method. Logistic regression was used to analyze the association between the polymorphism and HCC susceptibility. Under co-dominant model, we found that the ins/del and del/del genotype of indel was associated with a significantly increased risk of HCC compared with its homozygote ins/ins (OR=1.39, 95%C.I.=1.03-1.87; OR=1.68, 95%C.I.=1.03-2.73, respectively). Presence of 40-bp deletion allele of MDM2 seemed to confer higher risk for HCC when compared with non-carriers (OR=1.30, 95%C.I.=1.06-1.60, P=0.011). Further stratification analysis showed that this association was more pronounced in patients with a family history of HCC, early tumor stage and higher serum alpha-fetoprotein (AFP). These findings indicated that the MDM2 indel polymorphism may be a genetic modifier for developing HCC in Chinese population.

Alpha-fetoprotein gene polymorphisms and risk of HCC and cirrhosis

BACKGROUND

Elevated level of alpha fetoprotein (AFP) is found in approximately 60% of hepatocellular carcinoma (HCC) cases. Other liver diseases including cirrhosis and chronic hepatitis are related with an increased level of AFP. The regulation of AFP gene expression has been relatively less studied although the gene has been suggested to play a role in HCC development. This study aimed at identifying genetic variations in AFP that might be associated with the presence of HCC and cirrhosis among ethnic Indonesians.

METHODS

Direct DNA sequencing was carried out to sequence AFP promoter, exons, and 3' untranslated region (UTR) in DNA samples isolated from 119 HCC, 119 cirrhosis and 105 control subjects. For each sample serum AFP level was determined and association studies with single nucleotide polymorphisms (SNPs) and haplotypes were performed.

RESULTS

In this study we identified 47 SNPs in the AFP gene. Statistically significant associations with HCC and cirrhosis were detected for six individual SNPs in the AFP promoter, AFP intron 1 and intron 2 (rs6834059, rs3796678, rs3796677, rs3796676, rs28532518 and rs4646038). Furthermore, we identified two SNPs in AFP intron 7 and 3'UTR, rs2298839 and rs10020432, which are associated with increased risk of cirrhosis.

CONCLUSION

Genetic variants in the AFP gene may be associated with HCC and cirrhosis risk for ethnic Indonesians.

Association between MDM2-SNP309 and hepatocellular carcinoma in Taiwanese population

AIM: To investigate the risk association and compare the onset age of hepatocellular carcinoma (HCC) patients in Taiwan with different genotypes of MDM2-SNP309.

METHODS: We analyzed MDM2-SNP309 genotypes from 58 patients with HCC and 138 cancer-free healthy controls consecutively. Genotyping of MDM2-SNP309 was conducted by restriction fragment length polymorphism assay.

RESULTS: The proportion of homozygous MDM2-SNP309 genotype (G/G) in cases and cancer-free healthy controls was similar (17.2% vs 16.7%). Multivariate analysis showed that the risk of G/G genotype of MDM2-SNP309 vs wild-type T/T genotype in patients with HCC was not significant (OR = 1.265, 95% CI = 0.074-21.77) after adjustment for sex, hepatitis B or C virus infection, age, and cardiovascular disease/diabetes. Nevertheless, there was a trend that GG genotype of MDM2-SNP309 might increase the risk in HCC patients infected with hepatitis virus (OR = 2.568, 95% CI = 0.054-121.69). Besides, the homozygous MDM2-SNP309 genotype did not exhibit a significantly earlier age of onset for HCC.

CONCLUSION: Current data suggest that the association between MDM2-SNP309 GG genotype and HCC is not significant, while the risk may be enhanced in patients infected by hepatitis virus in Taiwan.

Gene polymorphisms related to angiogenesis, inflammation and thrombosis that influence risk for oral cancer

Genetic association studies have implicated functional DNA polymorphisms in genes encoding factors related to angiogenesis, inflammation and thrombosis with increased risk for oral squamous cell carcinoma (OSCC). This study examines possible interactions between nine such genotype polymorphisms and their combinatory effect in assessing the OSCC risk in a European population. OSCC cases (N=162) and healthy controls (N=168) of comparable age, gender, and ethnicity (Greeks and Germans) were studied. Multivariate logistic regression models were constructed in order to assess the contribution of homozygous or heterozygous variant genotypes of polymorphisms MMP-1 (-1607 1G/2G), MMP-3 (-1171 5A/6A), MMP-9 (-1562C/T), TIMP-2 (-418C/G), VEGF (+936C/T), GPI-alpha (+807C/T), PAI-1 (4G/5G), ACE (intron 16D/I) and TAFI (+325C/T) upon overall, early and advanced stages of OSCC. Four out of nine polymorphisms affecting PAI-1, MMP-9, TIMP-2 and ACE expression contributed significantly in OSCC prediction in the various logistic regression models. Based on these findings and previous reports, possible interactions of the implicated factors leading to OSCC development, as well as an algorithm of risk estimation are discussed.