Role of OCT1 in hepatocellular carcinoma

Model informed drug development: HSK21542 PBPK model supporting dose decisions in specific populations

HKS21542, a highly selective activator of peripheral kappa opioid receptor agonists, plays a critical role in antinociception and itch inhibition during clinical development. Due to its indication population and elimination characteristics, it is imperative to evaluate the potential HSK21542 systemic exposure in individuals with renal impairment, hepatic impairment, the elderly, and the geriatric population. Here, a physiologically-based pharmacokinetic (PBPK) model for HSK21542 was developed based on in vitro metabolism and transport characteristics and in vivo elimination mechanism. Meanwhile, the potential systemic exposure of HSK21542 in specific populations was evaluated. The predicted results indicated increased systemic exposure in patients with renal impairment, hepatic impairment and in the elderly. Compared to the healthy volunteers aged 20-60 years, the AUC0-24h increased by 52 %-71 % in population with moderate to severe renal impairment, by 46 %-77 % in those with mild to severe hepatic impairment, and by 45 %-85 % in the elderly population aged 65-95-years. Conversely, the pediatric population demonstrated a potential decrease in systemic exposure, ranging from 20 % to 37 % in patients aged 0-17 years due to the physiological characteristics. Combined with the predicted results and the exposure-response relationship observed for HSK21542 and its analog (CR845), dosage regimens were designed for the target population with renal and hepatic impairment, supporting the successfully conducted trials (CTR20201702 and CTR20211940). Moreover, the observed exposure of HSK21542 in the elderly closely matched the predicted results within the same age group. Additionally, based on the predicted results, potential reductions in systemic exposure in pediatric patients should be carefully considered to avoid potential treatment failure in future clinical trials.

Immunotherapy and drug sensitivity predictive roles of a novel prognostic model in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most significant causes of cancer-related deaths in the worldwide. Currently, predicting the survival of patients with HCC and developing treatment drugs still remain a significant challenge. In this study, we employed prognosis-related genes to develop and externally validate a predictive risk model. Furthermore, the correlation between signaling pathways, immune cell infiltration, immunotherapy response, drug sensitivity, and risk score was investigated using different algorithm platforms in HCC. Our results showed that 11 differentially expressed genes including UBE2C, PTTG1, TOP2A, SPP1, FCN3, SLC22A1, ADH4, CYP2C8, SLC10A1, F9, and FBP1 were identified as being related to prognosis, which were integrated to construct a prediction model. Our model could accurately predict patients' overall survival using both internal and external datasets. Moreover, a strong correlation was revealed between the signaling pathway, immune cell infiltration, immunotherapy response, and risk score. Importantly, a novel potential drug candidate for HCC treatment was discovered based on the risk score and also validated through ex vivo experiments. Our finds offer a novel perspective on prognosis prediction and drug exploration for cancer patients.

High Matrix Metalloproteinase 28 Expression is Associated with Poor Prognosis in Pancreatic Adenocarcinoma

Purpose

Pancreatic adenocarcinoma (PAAD) is a devastating disease with high mortality and morbidity. Matrix metalloproteinase 28 (MMP28) has been associated with carcinogenesis of many human cancers. However, little is known about the potential prognostic value and underlying regulatory mechanisms of MMP28 in PAAD.

Methods

The relationship between MMP28 expression level and various clinicopathological parameters was analyzed in TCGA-PAAD cohorts. MMP28-correlated genes in the TCGA-PAAD cohort were identified and enrichment analysis according to the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes was conducted using LinkedOmics. Protein–protein interaction and transcription factors-miRNA co-regulatory networks were constructed with the use of NetworkAnalyst. Then, the distribution of immune cells related to MMP28 expression in blood was analyzed using the Human Protein Atlas, and the tumor microenvironment of PAAD was analyzed by the TIMER 2.0 database. To investigate the biological function of MMP28 in PAAD, siRNA was constructed to knock down the MMP28 gene in vitro.

Results

High MMP28 expression is associated with poor overall survival and disease-free survival in PAAD patients. The expression of MMP28 in PAAD is most significantly correlated with KRT19, IL1RN, and ANXA2 genes. Network analysis revealed that MIR-181 family, TAFs, and CDC6 are potential regulators of MMP28. Furthermore, naive CD4⁺ T cell, naive CD8⁺ T cell, and mucosal-associated invariant T cell enrichment in blood were correlated with MMP28 expression. Furthermore, high MMP28 expression was correlated with a decrease in B cell, naive CD4⁺ T cell, naive CD8⁺ T cell, and endothelial cell presence in the tumor microenvironment in PAAD. Finally, genetic knockdown of MMP28 could restrain the proliferation, migration, and invasion of PAAD cells.

Conclusion

Our findings indicate that high MMP28 expression in PAAD is associated with cancer progression, invasion, and metastasis. Hence, MMP28 might serve as an independent prognostic biomarker and a prospective therapeutic target for PAAD.

Bile formation and secretion: An update

Bile formation is a fundamental physiological process that is vital to the survival of all vertebrates. However, little was known about the mechanisms of this secretion until after World War II. Initial studies involved classic physiologic studies in animal models and humans, which progressed to include studies in isolated cells and membrane vesicles. The advent of molecular biology then led to the identification of specific transport systems that are the determinants of this secretion. Progress in this field was reviewed in the American Physiologic Society's series on "Comprehensive Physiology" in 2013. Herein, we provide an in-depth update of progress since that time.

Role of ATP-binding Cassette Transporters in Sorafenib Therapy for Hepatocellular Carcinoma: an overview

BACKGROUND

Molecular therapy with sorafenib remains the mainstay for advanced-stage hepatocellular carcinoma. Notwithstanding, treatment efficacy is low, with few patients obtaining long-lasting benefits due to the high chemoresistance rate.

OBJECTIVE

To perform, for the first time, an overview of the literature concerning the role of adenosine triphosphate-binding cassette (ABC) transporters in sorafenib therapy for hepatocellular carcinoma.

METHODS

Three online databases (PubMed, Web of Science and Scopus) were searched, from inception to October 2020. Studies selection, analysis and data collection was independently performed by two authors.

RESULTS

The search yielded 224 results; 29 were selected for inclusion. Most studies were pre-clinical, using HCC cell lines; three used human samples. Studies highlight the effect of sorafenib in decreasing ABC transporters expression. Conversely, it is described the role of ABC transporters, particularly multidrug resistance protein 1 (MDR-1), multidrug resistance-associated proteins 1 and 2 (MRP-1 and MRP-2) and ABC subfamily G member 2 (ABCG2) in sorafenib pharmacokinetics and pharmacodynamics, being key resistance factors. Combination therapy with naturally available or synthetic compounds that modulate ABC transporters may revert sorafenib resistance, by increasing absorption and intracellular concentration.

CONCLUSION

A deeper understanding of ABC transporters' mechanisms may provide guidance for developing innovative approaches for hepatocellular carcinoma. Further studies are warranted to translate the current knowledge into practice and paving the way to individualized therapy.

Polysaccharides of vinegar-baked radix bupleuri promote the hepatic targeting effect of oxymatrine by regulating the protein expression of HNF4α, Mrp2, and OCT1

ETHNOPHARMACOLOGICAL RELEVANCE

Vinegar-baked Radix Bupleuri (VBRB) is a processed form of Bupleurum chinense DC. As a well-known meridian-guiding drug, it is traditionally used as a component of traditional Chinese medicine formulations indicated for the treatment of liver diseases. However, the liver targeting component in VBRB remains unclear. Therefore, this study aims to explore the efficacy and mechanism of PSS (polysaccharides in Vinegar-baked Radix Bupleuri) in enhancing liver targeting.

MATERIALS AND METHODS

Drug distribution of OM alone or combined with PSS was investigated in vivo. Relative uptake efficiency (RUE) and relative targeting efficiency (RTE) were calculated to evaluate liver targeting efficiency. The mRNA and protein expression of organic cation transporter 1 (OCT1), multi-drug resistance protein 2 (Mrp2), and hepatocyte nuclear factor 4α (HNF4α) in the liver were determined by q-PCR and Western blot. Then, AZT, the inhibitor of OCT1 and BI6015, the inhibitor of HNF4α were used to investigate regulatory mechanisms involved in the uptake of OM in the cell. At last, the role of PSS in the anti-hepatitis B virus (HBV) was explored on HepG2.2.15.

RESULTS

PSS increased the AUC of OM in the liver and increase the RUE and RTE in the liver which indicated a liver targeting enhancing effect. The mRNA and protein expression of OCT1 was increased while Mrp2 and HNF4α decreased. PSS could increase the uptake of OM in HepG2 by increasing the protein expression of HNF4α and OCT1, while inhibited Mrp2. Moreover, PSS combined with OM could enhance the anti-HBV effect of OM.

CONCLUSION

PSS enhanced the liver targeting efficiency and the underlying mechanism related to up-regulating the expression of OCT1 and HNF4α, while down-regulating of Mrp2. These results suggest that PSS may become a potential excipient and provide a new direction for new targeted research.

Drug-Drug Interactions at Organic Cation Transporter 1

The interaction between drugs and various transporters is one of the decisive factors that affect the pharmacokinetics and pharmacodynamics of drugs. The organic cation transporter 1 (OCT1) is a member of the Solute Carrier 22A (SLC22A) family that plays a vital role in the membrane transport of organic cations including endogenous substances and xenobiotics. This article mainly discusses the drug-drug interactions (DDIs) mediated by OCT1 and their clinical significance.