Prognostic value of genotyping in hepatocellular carcinoma: A systematic review

Primary liver cancer is the sixth most commonly diagnosed cancer and the third leading cause of cancer death. Advances in sequencing technology are opening genomics to widespread application for diagnosis and research. The poor prognosis of advanced HCC warrants a personalized approach. The objective was to assess the value of genotyping for risk stratification and prognostication of HCC. We performed a systematic review of manuscripts published on MEDLINE from 1 January 2009 to 1 January 2022, addressing the value of genotyping for HCC risk stratification and prognostication. Publication information for each has been collected using a standardized data extraction form. Twenty-five articles were analysed. This study showed that various genomics approaches (i.e., NGS, SNP, CASP or polymorphisms in circadian genes' association) provided predictive and prognostic information, such as disease control rate, median progression-free survival, and shorter median overall survival. Genotyping, which advances in understanding the molecular origin, could be a solution to predict prognosis or treatment response in patients with HCC.

ASCT2 and LAT1 Contribution to the Hallmarks of Cancer: From a Molecular Perspective to Clinical Translation

The role of the amino acid transporters ASCT2 and LAT1 in cancer has been explored throughout the years. In this review, we report their impact on the hallmarks of cancer, as well as their clinical significance. Overall, both proteins have been associated with cell death resistance through dysregulation of caspases and sustainment of proliferative signaling through mTOR activation. Furthermore, ASCT2 appears to play an important role in cellular energetics regulation, whereas LAT1 expression is associated with angiogenesis and invasion and metastasis activation. The molecular impact of these proteins on the hallmarks of cancer translates into various clinical applications and both transporters have been identified as prognostic factors in many types of cancer. Concerning their role as therapeutic targets, efforts have been undertaken to synthesize competitive or irreversible ASCT2 and LAT1 inhibitors. However, JHP203, a selective inhibitor of the latter, is, to the best of our knowledge, the only compound included in a Phase 1 clinical trial. In conclusion, considering the usefulness of ASCT2 and LAT1 in a variety of cancer-related pathways and cancer therapy/diagnosis, the development and testing of novel inhibitors for these transporters that could be evaluated in clinical trials represents a promising approach to cancer prognosis improvement.

Genetic variants in glutamine metabolic pathway genes predict cutaneous melanoma-specific survival

Glutamine dependence is a unique metabolic defect seen in cutaneous melanoma (CM), directly influencing the treatment and prognosis. Here, we investigated the associations between 6025 common single-nucleotide polymorphisms (SNPs) in 77 glutamine metabolic pathway genes with CM-specific survival (CMSS) using genotyping datasets from two published genome-wide association studies (GWASs). In the single-locus analysis, 76 SNPs were found to be significantly associated with CMSS (P < .050, false-positive report probability < 0.2 and Bayesian false discovery probability < 0.8) in the discovery dataset, of which seven SNPs were replicated in the validation dataset and three SNPs (HAL rs17676826T > C, LGSN rs12663017T > A, and NOXRED1 rs8012548A > G) independently predicted CMSS, with an effect-allele attributed adjusted hazards ratio of 1.52 (95% confidence interval = 1.19-1.93) and P < .001, 0.68 (0.54-0.87) and P = .002 and 0.62 (0.46-0.83) and P = .002, respectively. The model including the number of unfavorable genotypes (NUGs) of these three SNPs and covariates improved the five-year CMSS prediction (P = .012) than the one with other covariates only. Further expression quantitative trait loci (eQTL) analysis found that the LGSN rs12663017 A allele was significantly associated with increased messenger RNA (mRNA) expression levels (P = 8.89 × 10 -11 ) in lymphoblastoid cell lines of the 1000 Genomes Project database. In the analysis of the genotype tissue expression (GTEx) project datasets, HAL rs17676826 C and NOXRED1 rs8012548 G alleles were significantly associated with their mRNA expression levels in sun-exposed skin of the lower leg (P = 6.62 × 10-6 and 1.37 × 10-7 , respectively) and in sun-not-exposed suprapubic skin (P < .001 and 1.43 × 10-8 , respectively). Taken together, these genetic variants of glutamine-metabolic pathway genes may be promising predictors of survival in patients with CM.

Simple and rapid radiosynthesis of N-18F-labeled glutamic acid as a hepatocellular carcinoma PET tracer

INTRODUCTION

We have reported that N-(2-¹⁸F-fluoropropionyl)-L-glutamate (¹⁸F-FPGLU) showed good tumor-to-background contrast and ¹⁸F-FPGLU was prepared via complex multi-step reaction sequence; here, it is synthesized by a facile two-step reaction sequence. The objectives of this study are to synthesize ¹⁸F-FPGLU via a two-step reaction sequence and to evaluate the value of ¹⁸F-FPGLU in nude mice bearing human hepatocellular carcinoma SMCC-7721 (HCC SMCC-7721).

METHODS

¹⁸F-FPGLU was synthetized from the precursor (2S)-dimethyl 2-(2-bromopropanamido)pentanedioate via the two-step on-column hydrolysis using a modified commercial FDG synthesizer. To investigate the transport mechanism of ¹⁸F-FPGLU, we conducted a series of competitive inhibition experiments on HCC SMCC-7721 cells in the absence or presence of Na⁺ and various types of inhibitors. Small-animal PET-CT imaging was performed on tumor-bearing nude mice using ¹⁸F-FPGLU and 2-¹⁸F-2-deoxy-D-glucose (¹⁸F-FDG).

RESULTS

The radiochemical yield of ¹⁸F-FPGLU was up to 15±5% (EOS, n=10) in 35min with the two-step procedure and the radiochemical purity was higher than 95% with a specific activity of 30-40GBq/μmol. In vitro cell experiments show that ¹⁸F-FPGLU is primarily transported through the Na⁺-dependent system X_AG- and Na⁺-independent system X_C-. PET imaging in a tumor model indicates that ¹⁸F-FPGLU may be superior to ¹⁸F-FDG for hepatocellular carcinoma (HCC) imaging.

CONCLUSION

An optimized route to prepare ¹⁸F-FPGLU was developed and ¹⁸F-FPGLU was synthetized from the precursor ((2S)-dimethyl 2-(2-bromopropanamido)pentanedioate) via the two-step on-column hydrolysis. ¹⁸F-FPGLU was a potential novel PET tracer for HCC imaging.