Sorafenib inhibits cancer side population cells by targeting c‑Jun N‑terminal kinase signaling

A novel SLC25A1 inhibitor, parthenolide, suppresses the growth and stemness of liver cancer stem cells with metabolic vulnerability

Liver cancer stem cells (LCSCs) are recognized as key contributors to hepatocarcinogenesis, progression, and recurrence. Consequently, eradicating LCSCs has a great chance of increasing long-term survival in patients with liver cancer. Parthenolide (PTL), a natural sesquiterpene lactone product, possesses robust antitumor activity. However, the effects of PTL on LCSCs and underlying mechanisms remain unknown. Here we show that administration of PTL stimulated cell cycle arrest at the G1 phase, induced apoptosis, and decreased the stemness of LCSCs. Further research indicates that PTL caused the production of ROS and the reduction of oxidative phosphorylation (OXPHOS) and mitochondrial membrane potential (MMP) levels of LCSCs. RNA sequencing (RNA-Seq) further shows that PTL decreased SLC25A1 expression at the mRNA level and that inhibition of SLC25A1 synergistically decreased the expression of IDH2 and several pivotal genes involved in mitochondrial respiratory chain complex, resulting in the production of ROS and mitochondrial dysfunction. In addition, the inhibitory effect of PTL on mitochondrial function and self-renewal capacity of LCSCs was abolished by the knockdown of SLC25A1 or treatment with SLC25A1 inhibitor CTPI-2. Importantly, PTL prevented liver cancer growth in vivo without clearly causing toxicity. Our research shows that PTL inhibits the growth and stemness of LCSCs through SLC25A1-mediated mitochondrial function. PTL may be a potential candidate natural agent for liver cancer treatment.

Diagnostic and therapeutic yields of early capsule endoscopy and device-assisted enteroscopy in the setting of overt GI bleeding: a systematic review with meta-analysis

BACKGROUND AND AIMS

Small-bowel capsule endoscopy (SBCE) and device-assisted enteroscopy (DAE) are essential in obscure GI bleeding (OGIB) management. However, the best timing for such procedures remains unknown. This meta-analysis aimed to compare, for the first time, diagnostic and therapeutic yields, detection of active bleeding and vascular lesions, recurrent bleeding, and mortality of "early" versus "nonearly" SBCE and DAE.

METHODS

MEDLINE, ScienceDirect, and Cochrane Central Register of Controlled Trials were searched to identify studies comparing early versus nonearly SBCE and DAE. Random-effects meta-analysis was performed; reporting quality was assessed.

RESULTS

From 1974 records, 39 were included (4825 patients). Time intervals for the early approach varied, within 14 days in SBCE and 72 hours in DAE. The pooled diagnostic and therapeutic yields of early DAE were superior to those of SBCE (7.97% and 20.89%, respectively; P < .05). The odds for active bleeding (odds ratio [OR], 5.09; I² = 53%), positive diagnosis (OR, 3.99; I² = 45%), and therapeutic intervention (OR, 3.86; I² = 67%) were higher in the early group for SBCE and DAE (P < .01). Subgroup effects in diagnostic yield were only identified for the early group sample size. Our study failed to identify differences when studies were classified according to time intervals for early DAE (I² < 5%), but the analysis was limited because of a lack of data availability. Lower recurrent bleeding in early SBCE and DAE was observed (OR, .40; P < .01; I² = 0%).

CONCLUSIONS

The role of small-bowel studies in the early evaluation of OGIB is unquestionable, impacting diagnosis, therapeutic intervention, and prognosis. Comparative studies are still needed to identify optimal timing.

Mechanisms of Pharmacoresistance in Hepatocellular Carcinoma: New Drugs but Old Problems

Hepatocellular carcinoma (HCC) is a malignancy with poor prognosis when diagnosed at advanced stages in which curative treatments are no longer applicable. A small group of these patients may still benefit from transarterial chemoembolization. The only therapeutic option for most patients with advanced HCC is systemic pharmacological treatments based on tyrosine kinase inhibitors (TKIs) and immunotherapy. Available drugs only slightly increase survival, as tumor cells possess additive and synergistic mechanisms of pharmacoresistance (MPRs) prior to or enhanced during treatment. Understanding the molecular basis of MPRs is crucial to elucidate the genetic signature underlying HCC resistome. This will permit the selection of biomarkers to predict drug treatment response and identify tumor weaknesses in a personalized and dynamic way. In this article, we have reviewed the role of MPRs in current first-line drugs and the combinations of immunotherapeutic agents with novel TKIs being tested in the treatment of advanced HCC.

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.

Molecular Bases of Drug Resistance in Hepatocellular Carcinoma

The poor outcome of patients with non-surgically removable advanced hepatocellular carcinoma (HCC), the most frequent type of primary liver cancer, is mainly due to the high refractoriness of this aggressive tumor to classical chemotherapy. Novel pharmacological approaches based on the use of inhibitors of tyrosine kinases (TKIs), mainly sorafenib and regorafenib, have provided only a modest prolongation of the overall survival in these HCC patients. The present review is an update of the available information regarding our understanding of the molecular bases of mechanisms of chemoresistance (MOC) with a significant impact on the response of HCC to existing pharmacological tools, which include classical chemotherapeutic agents, TKIs and novel immune-sensitizing strategies. Many of the more than one hundred genes involved in seven MOC have been identified as potential biomarkers to predict the failure of treatment, as well as druggable targets to develop novel strategies aimed at increasing the sensitivity of HCC to pharmacological treatments.

A novel multi-target RNAi adenovirus inhibits hepatoma cell proliferation, migration, and induction of angiogenesis

The pathogenesis of hepatocellular carcinoma (HCC) is a multi-step process involving many genes. Consequently, single gene targeting therapy has limited efficacy, making combination therapy targeting multiple genes a necessity. Based on our previous findings, we constructed a single vector mediating simultaneous expression of multiple short hairpin RNAs (shRNAs) against human vascular endothelial growth factor receptor 2 (VEGFR2), chemokine C-C motif receptor 1 (CCR1), and epithelial cell adhesion molecule (EpCAM), three genes closely related to HCC progression that act through separate pathways. The shRNA vector efficiently downregulated the mRNA and protein of all three molecules in Huh7 hepatoma cells. The vector also inhibited cell proliferation and migration and reduced angiogenesis. Furthermore, this shRNA vector can be recombined into adenovirus, a gene therapy vector, for better in vivo application. It thus offers a potentially effective future gene therapy approach to treating human liver cancer.

Regulatory mechanisms and therapeutic targeting of liver cancer stem cells

As cancer stem cells have been confirmed in many human solid tumors, hepatocellular carcinoma has been considered a stem cell disease. The existence of liver cancer stem cells in liver cancer has been a research hotspot recently. Cancer stem cell theory believes that tumorigenesis, development, metastasis, recurrence and drug resistance are closely associated with cancer stem cells. Therefore, the isolation and identification of liver cancer stem cells play a very important role in early prevention, early diagnosis, effective therapy and improving prognosis of liver cancer. This paper summarizes the origin, surface molecular markers, signal transduction and regulation of liver cancer stem cells, and discusses the therapies targeting liver cancer stem cells.