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This study aimed to explore the mechanism of alcohol-induced Osteonecrosis of the femoral head (ONFH) through in vivo and in vitro experiments. In vitro , the Oil Red O staining showed that ethanol promoted extracellular adipogenesis in a dose-dependent manner. ALP staining and alizarin red staining showed that ethanol inhibited the formation of extracellular mineralization in a dose-dependent manner. The Oil Red O staining showed that miR122 mimics and Lnc-HOTAIR SiRNA rescued extracellular adipogenesis induced by ethanol in BMSCs. Besides, we found that the high expression of PPARγ in BMSCs recruited histone deacetylase 3 (HDAC3) and histone methyltransferase (SUV39H1), which reduced the histone acetylation level and increased the histone methylation level in the miR122 promoter region, respectively. In vivo, the levels of H3K9ac, H3K14ac, and H3K27ac of miR122 promoter region in the ethanol group were significantly decreased compared to the control group, respectively. The levels of H3K9me2 and H3K9me3 of miR122 promoter region in the ethanol group were significantly increased compared to the control group. Lnc-HOTAIR/miR-122/PPARγ signaling mediated the alcohol-induced ONFH in the rat model. Furthermore, the persistent decrease of miR122 expression mediated the continuous progress of alcohol-induced ONFH after stopping alcohol consumption. • The increased adipogenic differentiation of BMSCs is an essential pathological process of alcohol-induced ONFH. • Lnc-HOTAIR/miR-122/PPARγ signaling mediated the adipogenic differentiation of BMSCs induced by ethanol. • Decrease expression of miR122 mediated the continuous progress of alcohol-induced ONFH after stopping alcohol consumption. [ABSTRACT FROM AUTHOR]

This discourse attempts to capture a few important dimensions of gut physiology like microbial homeostasis, short chain fatty acid (SCFA) production, occludin expression, and gut permeability in post-natal life of mice those received arsenic only during pre-natal life. Adult Balb/c mice were fed with 4 ppm arsenic trioxide in drinking water during breeding and gestation. After the birth of the pups, the arsenic water was withdrawn and replaced with clean drinking water. The pups were allowed to grow for 28 days (pAs-mice) and age matched Balb/c mice which were never exposed to arsenic served as control The pAs-mice showed a striking reduction in Firmicutes to Bacteroidetes (F/B) ratio coupled with a decrease in tight junction protein, occludin resulting in an increase in gut permeability, increased infiltration of inflammatory cells in the colon and decrease in common SCFAs in which butyrate reduction was quite prominent in fecal samples as compared to normal control. The above phenotypes of pAs-mice were mostly reversed by supplementing 5% sodium butyrate (w/w) with food from 21st to 28th day. The ability of butyrate in enhancing occludin expression, in particular, was dissected further. As miR122 causes degradation of Occludin mRNA, we transiently overexpressed miR122 by injecting appropriate plasmids and showed reversal of butyrate effects in pAs-mice. Thus, pre-natal arsenic exposure orchestrates variety of effects by decreasing butyrate in pAs-mice leading to increased permeability due to reduced occludin expression. Our research adds a new dimension to our understanding that pre-natal arsenic exposure imprints in post-natal life while there was no further arsenic exposure. • Prenatal Arsenic exposure decreases prevalence of butyrate producing bacteria and butyrate production in the gut. • Lack of butyrate production in the gut is responsible for increased permeability and decreased occludin expression. • Oral supplementation with butyrate reverses the prenatal arsenic induced changes in the gut. • Butyrate increases Occludin gene expression by downregulating miR122 in the gut. [ABSTRACT FROM AUTHOR]

Drug-induced liver injury (DILI) is a challenging clinical problem with respect to both diagnosis and management. As a newly emerging biomarker of liver injury, miR122 shows great potential in early and sensitive in situ detection of DILI. Glycyrrhetinic acid (GA) possesses desirable therapeutic effect on DILI, but its certain dose-dependent side effects after long-term and/or high-dose administration limit its clinical application. In this study, in order to improve the precise diagnosis and effective treatment of DILI, GA loaded all-in-one theranostic nanoplatform was designed by assembling of upconversion nanoparticles and gold nanocages. As a proof of concept, we demonstrated the applicability of this single-wavelength laser-triggered theranostic nanoplatform for the spatiotemporally controllable in situ imaging of DILI and miR122-controlled on-demand drug release in vitro and in vivo. This novel nanoplatform opens a promising avenue for the clinical diagnosis and treatment of DILI.

Xiaoying Wang,1,2,* Jiefu Peng,2,3,* Jing Wang,4,* Miao Li,2 Di Wu,2 Songyan Wu,2 Jipei Liao,2 Jun Dou2 1Department of Basis Medicine, Wuxi School of Medicine, Jiangnan University, Wuxi, People’s Republic of China; 2Department of Pathogenic Biology and Immunology, School of Medicine, Southeast University, Nanjing, People’s Republic of China; 3Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, People’s Republic of China; 4Department of Gynecology & Obstetrics, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, People’s Republic of China *These authors contributed equally to this work Background: Despite the breadth of understanding the noncoding RNAs’ function in molecular biology, their functional roles in hepatocellular carcinoma (HCC) is poorly understood. In this study, we investigated the effect of hepatitis C virus (HCV) core upon the expression of noncoding RNAs. Methods: The lncRNAs, mRNAs, and circRNAs were employed for identification of HCV core protein gene expression in human Huh7 hepatoma (Huh7) cell line. In data analysis, we applied a threshold that eliminated all genes that were not increased or decreased by at least a 2-fold change in a comparison between transfected and control cells. Hierarchical Clustering and the Kyoto encyclopedia of genes and genome pathway analyses were performed to show the distinguishable lncRNA, mRNAs, and circRNAs expression pattern among samples.Results: The array data showed that 4,851 lncRNAs, 4,785 mRNAs, and 823 circRNAs were 2-fold up-regulated but 3,569 lncRNAs, 3,192 mRNAs, and 419 circRNAs were 2-fold down-regulated in Huh 7-core cells. The genes in the enriched set were associated with macromolecule and nucleic acid metabolic processes, DNA damage response and regulation of voltage-gated calcium channel. We identified 10 genes from the selected 14 genes that were higher or lower expression in Huh7-core cells than that of Huh7-vector cells by quantitative real-time polymerase chain reaction. Interestingly, overexpression of miR122 and miR204 partly abrogated the expression of TGFBRAP1 and HOTTIP, and increased the HPCAL1 expression in the predicted carcinogenic pathways. Conclusion: Our data suggests that the pathways of miR204-HPCAL1-lncRNAHOTTIP and miR122-TGFBRAP1 were likely involved in the carcinogenic progress due to the presence of HCV core, and that overexpression of miR122 and miR204 might inhibit the HCC progress by down-regulation of TGFBRAP1 and HOTTIP expression. Keywords: hepatitis C virus, Core, lncRNA microarray, gene expression, hepatocellular carcinoma, miR122, HOTTIP

The hepatitis C virus RNA genome possesses a variety of conserved structural elements, in both coding and non-coding regions, that are important for viral replication. These elements are known or predicted to modulate key life cycle events, such as translation and genome replication, some involving conformational changes induced by long-range RNA–RNA interactions. One such element is SLVI, a stem-loop (SL) structure located towards the 5′ end of the core protein-coding region. This element forms an alternative RNA–RNA interaction with complementary sequences in the 5′ untranslated regions that are independently involved in the binding of the cellular microRNA 122 (miR122). The switch between ‘open’ and ‘closed’ structures involving SLVI has previously been proposed to modulate translation, with lower translation efficiency associated with the ‘closed’ conformation. In the current study, we have used selective 2′-hydroxyl acylation analysed by primer extension to validate this RNA–RNA interaction in the absence and presence of miR122. We show that the long-range association (LRA) only forms in the absence of miR122, or otherwise requires the blocking of miR122 binding combined with substantial disruption of SLVI. Using site-directed mutations introduced to promote open or closed conformations of the LRA we demonstrate no correlation between the conformation and the translation phenotype. In addition, we observed no influence on virus replication compared to unmodified genomes. The presence of SLVI is well-documented to suppress translation, but these studies demonstrate that this is not due to its contribution to the LRA. We conclude that, although there are roles for SLVI in translation, the LRA is not a riboswitch regulating the translation and replication phenotypes of the virus.

Abstract Hepatocellular carcinoma (HCC) is a cancer which occurs in liver and severity of this cancer makes it the sixth most prevalent cancer and second leading cause of death among all cancers. The load of hepatitis-B virus (HBV) in serum is one of the important risk factors for the HCC. Several other factors also contribute to the HBV associated malignant hepatoma (HCC) i.e. HBV mutation, integration and condition of the host. Transformation of the liver to HBV-associated HCC usually accompanies long-run symptoms i.e. inflammation and cirrhosis of the liver and infective agent load could be a vigorous prognosticator for each incidence and progression of this carcinoma. One of the prominent factors i.e. HBV X supermolecule (HBx) interferes with many signal pathways that are related to the proliferation and apoptosis of hepatic cells. Besides, HBx C-terminal truncation is also responsible for HCC. Longtime HBV infection causes risk of HCC; thus most of the study related to HBV (85%) is limited to HBV endemic regions. In this review, we have outlined the molecular mechanisms that come from other than HBV endemic places which can be innovative approaches to treat HCC. Graphical abstract Image 1 Highlights • Hepatitis-B virus (HBV) is a para-retrovirus with double-stranded DNA genome, HBVcauses one of the important risk factors for the HCC. • Transformation of the liver to HBV-associated HCC usually accompanies long-run symptoms i.e. inflammation and cirrhosis of the liver and infective agent load could be a vigorous prognosticator for each incidence and progression of this carcinoma. [ABSTRACT FROM AUTHOR]

The hepatitis C virus RNA genome possesses a variety of conserved structural elements, in both coding and non-coding regions, that are important for viral replication. These elements are known or predicted to modulate key life cycle events, such as translation and genome replication, some involving conformational changes induced by long-range RNA-RNA interactions. One such element is SLVI, a stem-loop (SL) structure located towards the 5' end of the core protein-coding region. This element forms an alternative RNA-RNA interaction with complementary sequences in the 5' untranslated regions that are independently involved in the binding of the cellular microRNA 122 (miR122). The switch between 'open' and 'closed' structures involving SLVI has previously been proposed to modulate translation, with lower translation efficiency associated with the 'closed' conformation. In the current study, we have used selective 2'-hydroxyl acylation analysed by primer extension to validate this RNA-RNA interaction in the absence and presence of miR122. We show that the long-range association (LRA) only forms in the absence of miR122, or otherwise requires the blocking of miR122 binding combined with substantial disruption of SLVI. Using site-directed mutations introduced to promote open or closed conformations of the LRA we demonstrate no correlation between the conformation and the translation phenotype. In addition, we observed no influence on virus replication compared to unmodified genomes. The presence of SLVI is well-documented to suppress translation, but these studies demonstrate that this is not due to its contribution to the LRA. We conclude that, although there are roles for SLVI in translation, the LRA is not a riboswitch regulating the translation and replication phenotypes of the virus. [ABSTRACT FROM AUTHOR]

Hepatocyte Nuclear Factor-4α (HNF-4α) is a key nuclear receptor protein required for liver development. miR-122 is a predominant microRNA expressed in liver and is involved in the regulation of cholesterol and fatty acid metabolism. HNF-4α is know to regulate expression of miR-122 in liver. We examined how HNF-4α regulated gluconeogenesis and lipid metabolism through miR-122 in vivo and in vitro. Expression of miR-122, HNF-4α, phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase), sterol response elementary binding protein-1 (SREBP-1), fatty acid synthase-1 (FAS-1), carnitine palmitoyltransferase-1 (CPT-1) and acetyl Coenzyme A carboxylase alpha (ACCα) were determined in livers of Type 2 diabetic mice and in insulin resistant palmitate-treated HepG2 cells. CPT-1 and phosphorylated ACCα expression were significantly decreased in livers of Type 2 diabetic mice and in palmitate-treated HepG2 cells compared to controls. In contrast, expression of miR-122, HNF-4α, PEPCK, G6Pase, SREBP-1, FAS-1 and ACCα were significantly elevated in liver of Type 2 diabetic mice and in palmitate-treated HepG2 cells compared to controls. Expression of HNF-4α increased whereas siRNA knockdown of HNF-4α decreased miR-122 levels in HepG2 cells compared to controls. In addition, expression of HNF-4α in HepG2 cells increased PEPCK, G6Pase, SREBP-1, FAS-1, ACCα mRNA and protein expression and decreased CPT-1 and p-ACCα mRNA and protein expression compared to controls. Addition of miR-122 inhibitors attenuated the HNF-4α mediated effect on expression of these gluconeogenic and lipid metabolism proteins. The results indicate that HNF-4α regulated miR-122 contributes to development of the gluconeogenic and lipid metabolism alterations observed in Type 2 diabetic mice and in palmitate-treated HepG2 cells. [ABSTRACT FROM AUTHOR]

Specific miRNA expression profiles have been shown to be associated with nonalcoholic fatty liver disease (NAFLD). We examined the correlation between the circulating levels and hepatic expression of miR122 and miR33a/b*, the key lipid metabolism-related gene expression and the clinicopathological factors of obese women with NAFLD. We measured miR122 and miR33a/b* expression in liver samples from 62 morbidly obese (MO), 30 moderately obese (ModO), and eight normal-weight controls. MiR122 and miR33a/b* expression was analyzed by qRT-PCR. Additionally, miR122 and miR33b* circulating levels were analyzed in 122 women. Hepatic miR33b* expression was increased in MO compared to ModO and controls, whereas miR122 expression was decreased in the MO group compared to ModO. In obese cohorts, miR33b* expression was increased in nonalcoholic steatohepatitis (NASH). Regarding circulating levels, MO patients with NASH showed higher miR122 levels than MO with simple steatosis (SS). These circulating levels are good predictors of histological features associated with disease severity. MO is associated with altered hepatic miRNA expression. In obese women, higher miR33b* liver expression is associated with NASH. Moreover, multiple correlations between miRNAs and the expression of genes related to lipid metabolism were found, that would suggest a miRNA-host gene circuit. Finally, miR122 circulating levels could be included in a panel of different biomarkers to improve accuracy in the non-invasive diagnosis of NASH. [ABSTRACT FROM AUTHOR]

Background: Hepatocellular carcinoma (HCC), a primary liver malignancy, is the most common cancer in males and fourth common cancer in females in Taiwan. HCC patients usually have a poor prognosis due to late diagnosis. It has been classified as a complex disease because of the heterogeneous phenotypic and genetic traits of the patients and a wide range of risk factors. Micro (mi)RNAs regulate oncogenes and tumor suppressor genes that are known to be dysregulated in HCC. Several studies have found an association between downregulation of miR-122, a liver-specific miRNA, and upregulation of paternally expressed gene 10 (PEG10) in HCC; however, the correlation between low miR-122 and high PEG10 levels still remains to be defined and require more investigations to evaluate their performance as an effective prognostic biomarker for HCC.Methods: An in silico approach was used to isolate PEG10, a potential miR-122 target implicated in HCC development. miR-122S binding sites in the PEG10 promoter were evaluated with a reporter assay. The regulation of PEG10 by miR-122S overexpression was examined by quantitative RT-PCR, western blotting, and immunohistochemistry in miR-122 knockout mice and liver tissue from HCC patients. The relationship between PEG10 expression and clinicopathologic features of HCC patients was also evaluated.Results: miR-122 downregulated the expression of PEG10 protein through binding to 3'-untranslated region (UTR) of the PEG10 transcript. In miR-122 knockout mice and HCC patients, the deficiency of miR-122 was associated with HCC progression. The expression of PEG10 was increased in 57.3 % of HCC as compared to paired non-cancerous tissue samples. However, significant upregulation was detected in 56.5 % of patients and was correlated with Okuda stage (P = 0.05) and histological grade (P = 0.001).Conclusions: miR-122 suppresses PEG10 expression via direct binding to the 3'-UTR of the PEG10 transcript. Therefore, while PEG10 could not be an ideal diagnostic biomarker for HCC but its upregulation in HCC tissue still has predictive value for HCC prognosis. [ABSTRACT FROM AUTHOR]

MicroRNA122 (miR122), a liver-specific microRNA, plays critical roles in homeostatic regulation and hepatic-specific differentiation. Induced pluripotent stem cells (iPSCs) have promising potential in regenerative medicine, but it remains unknown whether non-viral vector-mediated miR122 delivery can enhance the differentiation of iPSCs into hepatocyte-like cells (iPSC-Heps) and rescue thioacetamide-induced acute hepatic failure (AHF) in vivo. In this study, we demonstrated that embedment of miR122 complexed with polyurethane-graft-short-branch polyethylenimine copolymer (PU-PEI) in nanostructured amphiphatic carboxymethyl–hexanoyl chitosan (CHC) led to dramatically enhanced miR122 delivery into human dental pulp-derived iPSCs (DP-iPSCs) and facilitated these DP-iPSCs to differentiate into iPSC-Heps (miR122-iPSC-Heps) with mature hepatocyte functions. Microarray and bioinformatics analysis further indicated that CHC/PU-PEI-miR122 promoted the gene-signature pattern of DP-iPSCs to shift into a liver-specific pattern. Furthermore, intrahepatic delivery of miR122-iPSC-Heps, but not miR-Scr-iPSC-Heps, improved liver functions and rescued recipient survival, and CHC-mediated delivery showed a better efficacy than that using phosphate buffered saline as a delivery vehicle. In addition, these transplanted miR122-iPSC-Heps remained viable and could produce circulatory albumin for 4 months. Taken together, our findings demonstrate that non-viral delivery of miR122 shortens the time of iPSC differentiation into hepatocytes and the delivery of miR122-iPSC-Heps using CHC as a vehicle exhibited promising hepatoprotective efficacy in vivo. miR122-iPSC-Heps may represent a feasible cell source and provide an efficient and alternative strategy for hepatic regeneration in AHF. [ABSTRACT FROM AUTHOR]

Specific miRNA expression profiles have been shown to be associated with nonalcoholic fatty liver disease (NAFLD). We examined the correlation between the circulating levels and hepatic expression of miR122 and miR33a/b*, the key lipid metabolism-related gene expression and the clinicopathological factors of obese women with NAFLD. We measured miR122 and miR33a/b* expression in liver samples from 62 morbidly obese (MO), 30 moderately obese (ModO), and eight normal-weight controls. MiR122 and miR33a/b* expression was analyzed by qRT-PCR. Additionally, miR122 and miR33b* circulating levels were analyzed in 122 women. Hepatic miR33b* expression was increased in MO compared to ModO and controls, whereas miR122 expression was decreased in the MO group compared to ModO. In obese cohorts, miR33b* expression was increased in nonalcoholic steatohepatitis (NASH). Regarding circulating levels, MO patients with NASH showed higher miR122 levels than MO with simple steatosis (SS). These circulating levels are good predictors of histological features associated with disease severity. MO is associated with altered hepatic miRNA expression. In obese women, higher miR33b* liver expression is associated with NASH. Moreover, multiple correlations between miRNAs and the expression of genes related to lipid metabolism were found, that would suggest a miRNA-host gene circuit. Finally, miR122 circulating levels could be included in a panel of different biomarkers to improve accuracy in the non-invasive diagnosis of NASH.

Drug-induced liver injury (DILI) is a challenging clinical problem with respect to both diagnosis and management. As a newly emerging biomarker of liver injury, miR122 shows great potential in early and sensitive in situ detection of DILI. Glycyrrhetinic acid (GA) possesses desirable therapeutic effect on DILI, but its certain dose-dependent side effects after long-term and/or high-dose administration limit its clinical application. In this study, in order to improve the precise diagnosis and effective treatment of DILI, GA loaded all-in-one theranostic nanoplatform was designed by assembling of upconversion nanoparticles and gold nanocages. As a proof of concept, we demonstrated the applicability of this single-wavelength laser-triggered theranostic nanoplatform for the spatiotemporally controllable in situ imaging of DILI and miR122-controlled on-demand drug release in vitro and in vivo . This novel nanoplatform opens a promising avenue for the clinical diagnosis and treatment of DILI., Competing Interests: The authors declare no conflict of interest., (© 2021 The Authors. Published by Elsevier Ltd.)

This review intends to uncover how information from large-scale genetic profiling (whole genome sequencing, and whole exome sequencing) of nonalcoholic fatty liver disease (NAFLD), as well as information from circulating transcriptomics (cell-free miRNAs) and metabolomics, contributes to the understanding of NAFLD pathogenesis. A further aim is to address the question of whether OMICs information is ready to be implemented in the clinics. The available evidence suggests that any new knowledge pertaining to molecular signatures associated with NAFLD and nonalcoholic steatohepatitis should be promptly translated into the clinical setting. Nevertheless, rigorous steps that must include validation and replication are mandatory before utilizing OMICs biomarkers in diagnostics to identify patients at risk of advanced disease, including liver cancer., Competing Interests: Conflict-of-interest statement: No potential conflicts of interest.

miR122 is the prevalent miRNA in adult healthy liver and it is responsible for liver stem cell differentiation towards hepatocyte lineage. Its expression is frequently lost in hepatocellular carcinoma (HCC). We studied the effects of restoring miR122 expression in a distinctive cell line derived from human HCC-BCLC9 cells-with a solid stem-like cell profile, high tumor initiating ability and undetectable miR122 expression. We generated a stable BCLC9 cell line that expresses miR122 (BCLC9-miR122). Restitution of miR122 in BCLC9 cells, decreases cell proliferation rate and reduces significantly tumor size in vivo. BCLC9-miR122 cells down-regulate expression of MYC, KLF4, FOXM1, AKT2 and AKT3 genes and up-regulate FOXO1 and FOXO3A gene expression. In addition, miR122 transfected cells decreased AKT2 kinase activation while decreased FOXO1 and FOXO3A protein inactivation. Reduction in tumor size in BCLC9-miR122 associated with an increase in p38MAPK protein expression and activation leading to a low phospho-ERK1/2 to phospho-p38 ratio. Treatment of miR122 positive cells with an inhibitor of TGFBR1 activation, abolished tumor dormancy program and recovered cell proliferation rate through a Smad-independent TGF-β response.HCC stem-like cells can be directed towards cell differentiation and tumor dormancy by restoring miR122 expression. We demonstrate, for the first time, that dormancy program is achieved through a Smad-independent TGF-β pathway. Restablishing miR122 expression is a promising therapeutic strategy that would work concurrently reducing tumor aggressiveness and decreasing disease recurrence.

Background: Hepatocellular carcinoma (HCC), a primary liver malignancy, is the most common cancer in males and fourth common cancer in females in Taiwan. HCC patients usually have a poor prognosis due to late diagnosis. It has been classified as a complex disease because of the heterogeneous phenotypic and genetic traits of the patients and a wide range of risk factors. Micro (mi)RNAs regulate oncogenes and tumor suppressor genes that are known to be dysregulated in HCC. Several studies have found an association between downregulation of miR-122, a liver-specific miRNA, and upregulation of paternally expressed gene 10 (PEG10) in HCC; however, the correlation between low miR-122 and high PEG10 levels still remains to be defined and require more investigations to evaluate their performance as an effective prognostic biomarker for HCC., Methods: An in silico approach was used to isolate PEG10, a potential miR-122 target implicated in HCC development. miR-122S binding sites in the PEG10 promoter were evaluated with a reporter assay. The regulation of PEG10 by miR-122S overexpression was examined by quantitative RT-PCR, western blotting, and immunohistochemistry in miR-122 knockout mice and liver tissue from HCC patients. The relationship between PEG10 expression and clinicopathologic features of HCC patients was also evaluated., Results: miR-122 downregulated the expression of PEG10 protein through binding to 3'-untranslated region (UTR) of the PEG10 transcript. In miR-122 knockout mice and HCC patients, the deficiency of miR-122 was associated with HCC progression. The expression of PEG10 was increased in 57.3 % of HCC as compared to paired non-cancerous tissue samples. However, significant upregulation was detected in 56.5 % of patients and was correlated with Okuda stage (P = 0.05) and histological grade (P = 0.001)., Conclusions: miR-122 suppresses PEG10 expression via direct binding to the 3'-UTR of the PEG10 transcript. Therefore, while PEG10 could not be an ideal diagnostic biomarker for HCC but its upregulation in HCC tissue still has predictive value for HCC prognosis.

Reduced expression of microRNA122 (miR122), a liver-specific microRNA, is frequent in hepatocellular carcinoma (HCC). However, its biological significances remain poorly understood. Because deregulated amino acid levels in cancers can affect their biological behavior, we determined the amino acid levels in miR122-silenced mouse liver tissues, in which intracellular arginine levels were significantly increased. The increased intracellular arginine levels were through upregulation of the solute carrier family 7 (SLC7A1), a transporter of arginine and a direct target of miR122. Arginine is the substrate for nitric oxide (NO) synthetase, and intracellular NO levels were increased in miR122-silenced HCC cells, with increased resistance to sorafenib, a multikinase inhibitor. Conversely, maintenance of the miR122-silenced HCC cells in arginine-depleted culture media, as well as overexpression of miR122 in miR122-low-expressing HCC cells, reversed these effects and rendered the cells more sensitive to sorafenib. Using a reporter knock-in construct, chemical compounds were screened, and Wee1 kinase inhibitor was identified as upregulators of miR122 transcription, which increased the sensitivity of the cells to sorafenib. These results provide an insight into sorafenib resistance in miR122-low HCC, and suggest that arginine depletion or a combination of sorafenib with the identified compound may provide promising approaches to managing this HCC subset.