Prevalence of aflatoxin B1 in liver biopsies of proven hepatocellular carcinoma in India determined by an in-house immunoperoxidase test

Comprehensive Review of Hepatocellular Carcinoma in India: Current Challenges and Future Directions

There is not much information on hepatocellular carcinoma (HCC) in India. Here, we review the existing data, available treatment choices, and future directions in HCC management. An extensive search was conducted through PubMed and MEDLINE for studies published between January 2000 and June 2022 on the epidemiology of HCC in India using the following key words: atezolizumab, BCLC staging, hepatocellular carcinoma, immune checkpoint inhibitors, immunotherapy, and programmed cell death ligand-1, with the filters humans and English language. The most frequent risk factors for the development of HCC in India include nonalcoholic fatty liver disease, hepatitis B virus and hepatitis C virus infection, liver cirrhosis, and alcohol intake. On the basis of new findings, the Barcelona Clinic Liver Cancer (BCLC) Staging Criteria need to be revised. As most cases in India are discovered at a later stage, curative treatments such as surgical resection, ablation, or liver transplantation may not be an option. Clinical trials are underway for a number of immune checkpoint drugs that target cytotoxic T-cell lymphocyte-4 and programmed cell death-1/programmed cell death-ligand 1. In India, phase III trials of atezolizumab in combination with other drugs are underway for the treatment of various malignancies. Renin angiotensin system inhibitors, antivirals, primary hepatocyte transplantation, and bioartificial liver devices are among the future options for the management of HCC. In developing countries like India, HCC is often diagnosed at an advanced stage because of a delay in routine testing or screening. Therefore, developing effective treatment regimens for such stages is critical. Immunotherapy is a promising treatment option that has the potential to increase overall response and survival rate.

Inhibition of Aflatoxin Formation in Aspergillus Species by Peanut ( Arachis hypogaea) Seed Stilbenoids in the Course of Peanut-Fungus Interaction

Common soil fungi, Aspergillus flavus and Aspergillus parasiticus, are opportunistic pathogens that invade preharvest peanut seeds. These fungi often produce carcinogenic aflatoxins that pose a threat to human and animal health through food chains and cause significant economic losses worldwide. Detection of aflatoxins and further processing of crops are mandated to ensure that contaminated agricultural products do not enter food channels. Under favorable conditions, the fungus-challenged peanut seeds produce phytoalexins, structurally related stilbenoids, capable of retarding fungal development. The purpose of the present study was to evaluate the potential influence of peanut phytoalexins on fungal development and aflatoxin formation in the course of peanut-fungus interaction. The present research revealed that during such interaction, aflatoxin formation was completely suppressed in A. flavus and A. parasiticus strains tested, when low concentrations of spores were introduced to wounded preincubated peanuts. In most of the experiments, when fungal spore concentrations were 2 orders of magnitude higher, the spores germinated and produced aflatoxins. Of all experimental seeds that showed fungal growth, 57.7% were aflatoxin-free after 72 h of incubation. The research provided new knowledge on the aflatoxin/phytoalexin formation in the course of peanut-fungus interaction.

Hepatocellular carcinoma in non-cirrhotic liver: A comprehensive review

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, which in turns accounts for the sixth most common cancer worldwide. Despite being the 6^th most common cancer it is the second leading cause of cancer related deaths. HCC typically arises in the background of cirrhosis, however, about 20% of cases can develop in a non-cirrhotic liver. This particular subgroup of HCC generally presents at an advanced stage as surveillance is not performed in a non-cirrhotic liver. HCC in non-cirrhotic patients is clinically silent in its early stages because of lack of symptoms and surveillance imaging; and higher hepatic reserve in this population. Interestingly, F3 fibrosis in non-alcoholic fatty liver disease, hepatitis B virus and hepatitis C virus infections are associated with high risk of developing HCC. Even though considerable progress has been made in the management of this entity, there is a dire need for implementation of surveillance strategies in the patient population at risk, to decrease the disease burden at presentation and improve the prognosis of these patients. This comprehensive review details the epidemiology, risk factors, clinical features, diagnosis and management of HCC in non-cirrhotic patients and provides future directions for research.

A Review on Dietary and Non-Dietary Risk Factors Associated with Gastrointestinal Cancer

INTRODUCTION

Cancer is a complex disease involving neoplasm of abnormal cells leading to development of tumor cells. Gene mutations result in aberrant gene expression, which is the major cause observed in all the cancers. The GLOBOCAN 2012 reported the highest age-standardized rates for cancer of the colorectum followed by stomach, liver, and esophagus, which are gastrointestinal cancers, and the new cases also followed the same order across the globe. Various risk factors are associated with different types of cancer which can be classified as dietary and non-dietary risk factors. The dietary risk factors include diet, alcohol, and nutrient deficiencies, whereas the non-dietary risk factors of cancers are tobacco, lifestyle choices, certain infections, occupational exposures, and environmental factors.

PURPOSE

The aim of this review is to focus on the dietary and non-dietary risk factors linked to gastrointestinal cancers, which could be beneficial in clinical decision-making.

Study of the genetic diversity of the aflatoxin biosynthesis cluster in Aspergillus section Flavi using insertion/deletion markers in peanut seeds from Georgia, USA

Aflatoxins are among the most powerful carcinogens in nature. The major aflatoxin-producing fungi are Aspergillus flavus and A. parasiticus. Numerous crops, including peanut, are susceptible to aflatoxin contamination by these fungi. There has been an increased use of RNA interference (RNAi) technology to control phytopathogenic fungi in recent years. In order to develop molecular tools targeting specific genes of these fungi for the control of aflatoxins, it is necessary to obtain their genome sequences. Although high-throughput sequencing is readily available, it is still impractical to sequence the genome of every isolate. Thus, in this work, the authors proposed a workflow that allowed prescreening of 238 Aspergillus section Flavi isolates from peanut seeds from Georgia, USA. The aflatoxin biosynthesis cluster (ABC) of the isolates was fingerprinted at 25 InDel (insertion/deletion) loci using capillary electrophoresis. All isolates were tested for aflatoxins using ultra-high-performance liquid chromatography. The neighbor-joining, three-dimension (3D) principal coordinate, and Structure analyses revealed that the Aspergillus isolates sampled consisted of three main groups determined by their capability to produce aflatoxins. Group I comprised 10 non-aflatoxigenic A. flavus; Group II included A. parasiticus; and Group III included mostly aflatoxigenic A. flavus and the three non-aflatoxigenic A. caelatus. Whole genomes of 10 representative isolates from different groups were sequenced. Although InDels in Aspergillus have been used by other research groups, this is the first time that the cluster analysis resulting from fingerprinting was followed by whole-genome sequencing of representative isolates. In our study, cluster analysis of ABC sequences validated the results obtained with fingerprinting. This shows that InDels used here can predict similarities at the genome level. Our results also revealed a relationship between groups and their capability to produce aflatoxins. The database generated of Aspergillus spp. can be used to select target genes and assess the effectiveness of RNAi technology to reduce aflatoxin contamination in peanut.

Characterization of small RNA populations in non-transgenic and aflatoxin-reducing-transformed peanut

Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumulation of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNA populations in a control line and in two transformed peanut lines that expressed an inverted repeat targeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B₁ than the controls. The objective was to determine the putative involvement of the small RNA populations in aflatoxin reduction. In total, 41 known microRNA (miRNA) families and many novel miRNAs were identified. Among those, 89 known and 10 novel miRNAs were differentially expressed in the transformed lines. We furthermore found two small interfering RNAs derived from the inverted repeat, and 39 sRNAs that mapped without mismatches to the genome of A. flavus and were present only in the transformed lines. This information will increase our understanding of the effectiveness of RNAi and enable the possible improvement of the RNAi technology for the control of aflatoxins.

Wnt-signalling pathways and microRNAs network in carcinogenesis: experimental and bioinformatics approaches

Over the past few years, microRNAs (miRNAs) have not only emerged as integral regulators of gene expression at the post-transcriptional level but also respond to signalling molecules to affect cell function(s). miRNAs crosstalk with a variety of the key cellular signalling networks such as Wnt, transforming growth factor-β and Notch, control stem cell activity in maintaining tissue homeostasis, while if dysregulated contributes to the initiation and progression of cancer. Herein, we overview the molecular mechanism(s) underlying the crosstalk between Wnt-signalling components (canonical and non-canonical) and miRNAs, as well as changes in the miRNA/Wnt-signalling components observed in the different forms of cancer. Furthermore, the fundamental understanding of miRNA-mediated regulation of Wnt-signalling pathway and vice versa has been significantly improved by high-throughput genomics and bioinformatics technologies. Whilst, these approaches have identified a number of specific miRNA(s) that function as oncogenes or tumour suppressors, additional analyses will be necessary to fully unravel the links among conserved cellular signalling pathways and miRNAs and their potential associated components in cancer, thereby creating therapeutic avenues against tumours. Hence, we also discuss the current challenges associated with Wnt-signalling/miRNAs complex and the analysis using the biomedical experimental and bioinformatics approaches.

Fungal infection and aflatoxin contamination in maize collected from Gedeo zone, Ethiopia

Aflatoxins contamination of maize exhibits a serious threat to human and animal health over the past few decades. To protect the safety of food commodities, regular monitoring for afltoxins in food is necessary. In the proposed study, we have followed a rapid and sensitive biosensor approach as well as thin layer chromatography method for quantification of aflatoxins. Our data demonstrate that all the samples tested were beyond the safety level of aflatoxins as determined by Food and Drug Administration and European Union. Results of fungal mycoflora evidenced the massive presence of Aspergillus species (75 %) followed by Fusarium (11 %), Penicillium (8 %) and Trichoderma (6 %) as characterized by biochemical and sporulation properties. Use of internationally developed biosensor for detection of fungal toxin in this work is the first approach that was utilized in the developing country like Ethiopia. In the end, we conclude that fungal contaminant and there metabolites are potential threat to the agricultural industry and require urgent intervention.

RNAi-mediated Control of Aflatoxins in Peanut: Method to Analyze Mycotoxin Production and Transgene Expression in the Peanut/Aspergillus Pathosystem

The Food and Agriculture Organization of the United Nations estimates that 25% of the food crops in the world are contaminated with aflatoxins. That represents 100 million tons of food being destroyed or diverted to non-human consumption each year. Aflatoxins are powerful carcinogens normally accumulated by the fungi Aspergillus flavus and A. parasiticus in cereals, nuts, root crops and other agricultural products. Silencing of five aflatoxin-synthesis genes by RNA interference (RNAi) in peanut plants was used to control aflatoxin accumulation following inoculation with A. flavus. Previously, no method existed to analyze the effectiveness of RNAi in individual peanut transgenic events, as these usually produce few seeds, and traditional methods of large field experiments under aflatoxin-conducive conditions were not an option. In the field, the probability of finding naturally contaminated seeds is often 1/100 to 1/1,000. In addition, aflatoxin contamination is not uniformly distributed. Our method uses few seeds per transgenic event, with small pieces processed for real-time PCR (RT-PCR) or small RNA sequencing, and for analysis of aflatoxin accumulation by ultra-performance liquid chromatography (UPLC). RNAi-expressing peanut lines 288-72 and 288-74, showed up to 100% reduction (p ≤ 0.01) in aflatoxin B1 and B2 compared to the control that accumulated up to 14,000 ng · g(-1) of aflatoxin B1 when inoculated with aflatoxigenic A. flavus. As reference, the maximum total of aflatoxins allowable for human consumption in the United States is 20 ng · g(-1). This protocol describes the application of RNAi-mediated control of aflatoxins in transgenic peanut seeds and methods for its evaluation. We believe that its application in breeding of peanut and other crops will bring rapid advancement in this important area of science, medicine and human nutrition, and will significantly contribute to the international effort to control aflatoxins, and potentially other mycotoxins in major food crops.

The Indian National Association for Study of the Liver (INASL) Consensus on Prevention, Diagnosis and Management of Hepatocellular Carcinoma in India: The Puri Recommendations

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality and healthcare expenditure in patients with chronic liver disease. There are no consensus guidelines on diagnosis and management of HCC in India. The Indian National Association for Study of the Liver (INASL) set up a Task-Force on HCC in 2011, with a mandate to develop consensus guidelines for diagnosis and management of HCC, relevant to disease patterns and clinical practices in India. The Task-Force first identified various contentious issues on various aspects of HCC and these issues were allotted to individual members of the Task-Force who reviewed them in detail. The Task-Force used the Oxford Center for Evidence Based Medicine-Levels of Evidence of 2009 for developing an evidence-based approach. A 2-day round table discussion was held on 9th and 10th February, 2013 at Puri, Odisha, to discuss, debate, and finalize the consensus statements. The members of the Task-Force reviewed and discussed the existing literature at this meeting and formulated the INASL consensus statements for each of the issues. We present here the INASL consensus guidelines (The Puri Recommendations) on prevention, diagnosis and management of HCC in India.

Risk factors for hepatocellular carcinoma in India

Hepatocellular carcinoma (HCC) is an important cause of death all over the world, more so in Asia and Africa. The representative data on epidemiology of HCC in India is very scanty and cancer is not a reportable disease in India and the cancer registries in India are mostly urban. 45 million people who are suffering from chronic Hepatitis B virus (HBV) infection and approximately 15 million people who are afflicted with chronic Hepatitis C virus (HCV) infection in India. HBV and HCV infection is considered an important etiologic factor in HCC. Positive association between HCC and consumption of alcohol where alcohol contribute as a cofactor for hepatotoxins and hepatitis viruses. Aflatoxin contamination in the diets, Hepatitis B virus infection and liver cirrhosis in Andhra Pradesh, India and direct chronic exposure to aflatoxins was shown to cause liver cirrhosis. Cirrhosis of liver of any cause lead to develop about 70%-90% of HCC. Aflatoxin interact synergistically with Hepatitis B virus (HBV)/Hepatitis C virus (HCV) infection which increase the risk of HCC. HBV infection, HBV infection with Aflatoxin exposure, viral infection and alcohol consumption leading to overt cirrhosis of the liver, alcohol consumption leading to cirrhosis of the liver with viral infection are the predominant risk factor for the development of HCC. HCV and alcohol are also associated with HCC in India. Indians develop diabetes at younger age, Asians have strong genetic susceptibility for type II diabetes. Diabetes mellitus is identified as a risk factor for HCC. Prevention of viral infection by universal vaccination against hepatitis virus, HCC surveillance program, preventing alcoholic liver diseases, fungal contamination of grains and ground crops to prevent basically Aflatoxin exposure are important measures to prevent liver diseases and HCC among those at risk.

The association between exposure to aflatoxin, mutation in TP53, infection with hepatitis B virus, and occurrence of liver disease in a selected population in Hyderabad, India

Aflatoxin B1 is a carcinogen produced by Aspergillus flavus and a few related fungi that are often present in many food substances. It interacts synergistically with Hepatitis B or C virus (HBV, HBC) infection, thereby increasing the risk of hepatocellular carcinoma (HCC). The G to T transversion at the third position of codon 249 (AGG) of the TP53 gene, substituting arginine to serine, is the most common aflatoxin-induced mutation linked to HCC. This study examined mutations in TP53 by PCR-RFLP analysis and by measurement of an aflatoxin-albumin adduct as a biomarker for human exposure of aflatoxin B1 by indirect-competitive ELISA, in samples collected from healthy controls as well as patients with hepatitis in Hyderabad, Andhra Pradesh, India. A total of 238 blood samples were analyzed the presence of the G to T mutation. Eighteen of these samples were from HBV-positive subjects, 112 of these were from subjects who had HBV-induced liver cirrhosis, and 108 samples were taken from subjects without HBV infection or liver cirrhosis (control group). The G to T mutation was detected in 10 samples, 8 of which were from subjects positive to both HBV and aflatoxin-albumin adduct in blood (p=0.07); whilst two were from individuals who were HBV-negative, but positive for the aflatoxin-albumin adduct (p=0.14). The aflatoxin-albumin adduct was detected in 37 of 238 samples, 29 samples were from HBV-positive subjects and eight were from individuals who were positive for both HBV and the TP53 mutation (p=0.07). The concentration of aflatoxin-albumin adduct ranged from 2.5 to 667pg/mg albumin. Despite low incidence of the G to T mutation, its detection in subjects positive to aflatoxin-adducts is indicative of a strong association between the mutation and aflatoxin exposure in India.

Genetic variants of heat shock protein A1L2437 and A1B1267 as possible risk factors for hepatocellular carcinoma in India

To study the role of heat shock protein A1L (HSPA1L) and A1B (HSPA1B) polymorphisms and subsequent risk of hepatocellular carcinoma (HCC) in India. Subjects enrolled included 185 cases of HCC, 182 cases of chronic hepatitis (CH) and 200 healthy controls. Genomic DNA was typed for HSPA1L2437 and HSPA1B1267 SNP using polymerase chain reaction with restriction fragment length polymorphism. Other risk factors were also analysed. Hepatitis B virus (HBV) infection, older age >35 years and high aflatoxin level in urine increased the risk of HCC. The frequencies of HSPA1L BB genotype and B allele in HCC were more than in CH [odds ratio (OR): 9.83; P = 0.000], but also in HBV-related HCC than Chronic Hepatitis B (CHB) [OR: 3.44; P = 0.004] and HCV-related HCC compared to CHC [OR: 6.32; P = 0.010]. The frequency of HSPA1B genotype in the homozygous state was more in CH [OR: 6.01; P = 0.001] and is a good marker to predict the risk of HCV-related CH (CHC) compared to controls. HCV-related HCC has a higher frequency of the B allele of HSPA1B than healthy controls [OR: 3.95; P = 0.000] and CHC [OR: 2.35; P = 0.000], respectively. The frequencies increased further significantly in CHC compared to healthy controls [OR: 9.26; P = 0.000]. The risk for the development of CH and HCC compared to healthy controls irrespective of the aetiology was significant in terms of the HSPA1B marker than HSPA1L in the Indian population.

Hepatic aflatoxin B1-DNA adducts and TP53 mutations in patients with hepatocellular carcinoma despite low exposure to aflatoxin B1 in southern Japan

BACKGROUND & AIMS

Hepatitis B or C virus infection is considered to be the main cause of hepatocellular carcinoma (HCC) in Japan. Aflatoxin B1 (AFB1) is a carcinogen associated with HCC in regions with high exposure. Mutations in codon 249, exon 7 are a hallmark of AFB1 exposure. Therefore, to clarify the role of AFB1 in hepatocarcinogenesis, we examined AFB1-DNA in liver tissue and sequenced TP53 in Japanese patients with HCC.

METHODS

Hepatocyte AFB1-DNA adducts were determined immunohistochemically and direct sequencing of TP53 was done to determine mutations in 188 of 279 patients who underwent hepatic resection for HCC. We assessed hepatitis C virus antibodies (HCV Ab) and HBSAg expression; patients without either were defined as having non-B non-C hepatocellular carcinoma (NBNC HCC).

RESULTS

AFB1-DNA adducts were detected in hepatocyte nuclei in 18/279 patients (6%), including 13/83 patients (16%) with NBNC HCC and 5/51 patients (10%) expressing hepatitis B surface antigen. None of the patients with HCV Ab (n=136) were positive for AFB1-DNA. The incidence of the G-T transversion and mutations in exon 7 of TP53 in patients with AFB1-DNA adducts were significantly higher in patients with than in patients without AFB1-DNA adducts. All three patients with the codon 249 AGG-AGT mutation had AFB1-DNA adducts.

CONCLUSION

Although exposure to AFB1 is thought to be low in Japan, it is still associated with hepatocarcinogenesis, particularly in NBNC HCC and hepatitis B individuals.

Role of aflatoxin B1 as a risk for primary liver cancer in north Indian population

OBJECTIVES

The present study was designed to determine whether aflatoxin B1 (AFB1) exposure has any role to play in hepatocellular carcinoma (HCC) patients from northern India.

DESIGN AND METHODS

A total of 266 HCC patients and 251 patients of chronic liver disease without-HCC were enrolled into the study. All samples were screened for serological markers for hepatitis B and C infections and levels of AFB1 in food and urine samples.

RESULTS

A threefold (OR=3.43) and five-fold (OR=5.47) increased risk of HCC was observed amongst HBV infection and AFB1-levels in food and urine samples, respectively. However, a non-significant risk was observed with respect to HCV infection (OR=1.27) and alcohol consumption (OR=1.18). A threefold (OR=3.15) increased risk of HCC was observed amongst cases of non-viral etiology with respect to urinary AFB1.

CONCLUSION

The data provides an exposure and disease risk information for establishing intervention studies to diminish the impact of aflatoxin exposure in Indian population.

Hepatitis B virus-associated hepatocellular carcinoma from India: role of viral genotype and mutations in CTNNB1 (beta-catenin) and TP53 genes

PURPOSE

Chronic hepatitis B virus (HBV) infection is the major risk factor for hepatocellular carcinoma (HCC) in India. Studies from other countries have linked HBV genotype C to a higher risk for HCC. This study was carried out to determine the association between genotype and HCC and also the frequency of mutations in CTNNB1 (beta-catenin) and TP53 genes in HBV-related HCC.

METHODS

Formalin-fixed paraffin-embedded (FFPE) tissues from 20 (15 autopsy, five resected specimens) cases of HBV-associated HCC were examined. Viral genotype was determined by sequencing portions of the HBV S gene using four overlapping PCR amplicons. Exon 3 of CTNNB1 and exon 7 of TP53 were sequenced.

RESULTS

HBV genotyping was possible in 14 of 20 cases; genotype D was most common (n = 11) followed by C (n = 2) and A (n = 1). CTNNB1 mutations were noted in two of 15 amplifiable cases while two of 10 specimens showed TP53 mutations.

CONCLUSIONS

HBV genotype can be ascertained from FFPE sections by sequencing multiple overlapping fragments to avoid the limitation of fragmented DNA. Genotype D was the common genotype in HBV-associated HCC. The very low frequency of TP53 mutation suggests low levels of aflatoxin B₁ exposure. The beta-catenin pathway appears not to be significantly involved in HBV-related HCC in India. However, further larger studies are required to confirm these findings.

Alpha-fetoprotein as a tumor marker in hepatocellular carcinoma: investigations in south Indian subjects with hepatotropic virus and aflatoxin etiologies

OBJECTIVES

The prevalence of hepatitis B virus (HBV) is reportedly the main cause of hepatocellular carcinoma (HCC) in India, where hepatitis C virus (HCV)-associated HCC is believed to be relatively less prevalent. We verified the usefulness of alpha-fetoprotein (AFP) as a tumor marker and analyzed the influence of viral etiology on AFP levels in HCC.

METHODS

Of a total of 1012 cases with liver disease, 202 were investigated for the presence of AFP (142 HCC cases, 30 cirrhosis cases, and 30 chronic liver disease (CLD) cases). In addition, serum samples from 30 healthy patients, 30 hepatitis B surface antigen (HBsAg) carriers, and 30 acute viral hepatitis cases were included as controls. AFP was quantitatively determined using a commercial ELISA (Quorum Diagnostics, Canada). Out of the 142 HCC cases screened for AFP, aflatoxin B1 (AFB1) detection was carried out in 38 HCC cases using an in-house immunoperoxidase test.

RESULTS

In HBV and HCV co-infected HCC cases, the AFP positivity was 85.7%. In HBV alone-associated HCC, the positivity was 62.9%, and 54.5% of AFB1 positive HCC cases showed AFP positivity. In HBV and HCV negative HCC cases, the positivity was 20.5%, and in HCV-associated HCC it was 17.6%. The HBV/HCV co-infected group and HBV alone positive HCC cases had significantly elevated levels of AFP. When AFP positivity was analyzed based on the marker profile of HBV, 89.7% of AFP positive cases were HBV-DNA positive.

CONCLUSIONS

The overall positivity pattern of AFP in HCC does indicate that higher levels of AFP are observed with hepatitis virus positivity, especially with HBV. Further studies must be carried out to correlate the serum levels of AFP with the size, number, and degree of differentiation of HCC nodules.