Hepatocellular carcinoma(HCC) is one of the most common tumors in the world. Human insulin-like growth factor 2(IGF2) mRNA binding protein 2(IGF2BP2) plays an important role in the progression of hepatocellular carcinoma. Additionally, long non-coding RNA(lncRNA) has been confirmed as a key regulator of hepatocellular carcinoma occurrence. However, the function of TRPC7-AS1 has not been verified in hepatocellular carcinoma. The research results revealed that high IGF2BP2 expression was associated with a decreased survival rate in patients with hepatocellular carcinoma. Furthermore, IGF2BP2 knockdown inhibited and IGF2BP2 overexpression promoted the cell proliferation and invasion of hepatocellular carcinoma cells. The research illuminated that IGF2BP2 regulated the expression of TRPC7-AS1, and a correlation was observed between IGF2BP2 and TRPC7-AS1 expression. TRPC7-AS1 silencing repressed and its overexpression promoted the progression of hepatocellular carcinoma. After silencing or overexpressing TRPC7-AS1, the expression of the high-mobility group AT-hook 2 (HMGA2) gene decreased or increased, respectively. IGF2BP2 enhanced the expression of TRPC7-AS1 and thus affected the expression of HMGA2, thereby promoting hepatocellular carcinoma progression.

Inducing protein degradation by proteolysis-targeting chimeras (PROTACs) has gained tremendous momentum in the field for its promise in the discovery and development of new therapies. Based on our previously reported PROTAC BCR-ABL degraders, we designed and synthesized additional 4 PROTAC compounds with a novel linker that contains pyrimidine rings. Molecular and cellular studies have shown that different linkers affect the degradation activity of small-molecule degraders on the target protein of BCR-ABL. We screened out a lead compound, DMP11, with stable physicochemical properties and high activity. Preliminary evaluation of its pharmacodynamics in vitro model showed that it has a good inhibitory effect on imatinib-resistant chronic myeloid leukemia cell lines, as has been shown in animal models. Our preliminary research into the mechanism of DMP11 found that DMP11 can overcome drug resistance by simultaneously inhibiting the targets of BCR-ABL and SRC-family kinase (SFK).

Background. 5-Fluorouracil (5-FU) has been widely applied in treating cancers. However, its usage is largely limited in hepatocellular carcinoma (HCC), due to acquired resistance. Here, we aim to identify target proteins and investigate their roles in 5-FU sensitivity of HCC cells. Methods. Mass spectrometry (MS) proteomics was performed on 5-FU-resistant cell line (BEL7402/5-FU) and its parental cell line (BEL7402) with 5-FU treatment. In order to identify potential targets, we compared the proteomics between two cell line groups and used bioinformatics tools to select hub proteins from all differentially expressed proteins. Results. We finally focused on a group of cell cycle-related kinases (CDKs). By CCK8 assay, we confirmed that the CDK inhibitor significantly decreased the IC₅₀ of 5-FU-resistant cells. Conclusions. Our study verified that CDK inhibition can reverse 5-FU resistance of HCC cells.

Due to resistance and BCR-ABL^T315I-mutated, CML remains a clinical challenge. It needs new potential therapeutic targets to overcome CML resistance related to BCR-ABL. Our research revealed that the deubiquitinating enzyme USP28 was highly expressed in BCR-ABL-dependent CML patients. Similarly, a high expression of USP28 was found in the K562 cell line, particularly in the imatinib-resistant strains. Notably, USP28 directly interacted with BCR-ABL. Furthermore, when BCR-ABL and its mutant BCR-ABL^T315I were overexpressed in K562-IMR, they promoted the expression of IFITM3. However, when small molecule inhibitors targeting USP28 and small molecule degraders targeting BCR-ABL were combined, they significantly inhibited the expression of IFITM3. The experiments conducted on tumor-bearing animals revealed that co-treated mice showed a significant reduction in tumor size, effectively inhibiting the progression of CML tumors. In summary, USP28 promoted the proliferation and invasion of tumor cells in BCR-ABL-dependent CML by enhancing the expression of IFITM3. Moreover, imatinib resistance might be triggered by the activation of the USP28-BCR-ABL-IFITM3 pathway. Thus, the combined inhibition of USP28 and BCR-ABL could be a promising approach to overcome CML resistance dependent on BCR-ABL.

Resistance to tyrosine kinase inhibitors (TKIs) is a core limitation in the clinical treatment of chronic myeloid leukemia (CML). Although ponatinib can cover the T315I mutation, its clinical application is limited by severe adverse reactions at high doses. On the basis of the USP28-BCR-ABL-IFITM3 resistance signaling axis first identified in our previous study, a ginger-derived lipid carrier-mediated targeted nanodelivery system (IP@GLPs@εF) was constructed, which codelivers CRISPR/Cas9-mediated IFITM3 knockout (IFITM3 KO) plasmid and ponatinib, establishing a new synergistic intervention mode of gene editing and targeted chemotherapy. When modified with ε-polylysine and fucoidan via layer-by-layer self-assembly technology, the carrier has an average particle size of 226.1 nm, a drug encapsulation efficiency of 84.2%, and excellent biocompatibility. In vitro experiments confirmed that the optimal ratio (2.5 μg IFITM3-sg3 + 5 μM ponatinib) significantly reversed the drug resistance of K562R cells, promoted apoptosis and inhibited proliferation. In vivo experiments using ectopic and orthotopic xenograft models verified that this system can efficiently target tumor tissues and significantly suppress the progression and metastasis of drug-resistant tumors, with no obvious toxic side effects on major organs. Mechanistically, this study revealed that IFITM3 mediates CML resistance by interacting with HSPA9 to activate the MET/AKT/BCL2 pathway and that IFITM3 KO can block this pathway and exert a synergistic antiresistance effect with ponatinib. This research provides a novel IFITM3-targeted synergistic therapeutic strategy and technical support for the clinical treatment of CML resistance.