Tumor immunotherapy resistance: Revealing the mechanism of PD-1 / PD-L1-mediated tumor immune escape.

Tumor immunotherapy, an innovative anti-cancer therapy, has showcased encouraging outcomes across diverse tumor types. Among these, the PD-1/PD-L1 signaling pathway is a well-known immunological checkpoint, which is significant in the regulation of immune evasion by tumors. Nevertheless, a considerable number of patients develop resistance to anti-PD-1/PD-L1 immunotherapy, rendering it ineffective in the long run. This research focuses on exploring the factors of PD-1/PD-L1-mediated resistance in tumor immunotherapy. Initially, the PD-1/PD-L1 pathway is characterized by its role in facilitating tumor immune evasion, emphasizing its role in autoimmune homeostasis. Next, the primary mechanisms of resistance to PD-1/PD-L1-based immunotherapy are analyzed, including tumor antigen deletion, T cell dysfunction, increased immunosuppressive cells, and alterations in the expression of PD-L1 within tumor cells. The possible ramifications of altered metabolism, microbiota, and DNA methylation on resistance is also described. Finally, possible resolution strategies for dealing with anti-PD-1/PD-L1 immunotherapy resistance are discussed, placing particular emphasis on personalized therapeutic approaches and the exploration of more potent immunotherapy regimens.

Exploring the pharmacological mechanism of Wuzhuyu decoction on hepatocellular carcinoma using network pharmacology.

BACKGROUND: Wuzhuyu decoction, a traditional Chinese medicinal formula, is effective in treating hepatocellular carcinoma (HCC). AIM: To explore the potential mechanism of action of Wuzhuyu decoction against HCC. METHODS: The active components of each Chinese herbal medicinal ingredient in Wuzhuyu decoction and their targets were obtained from the Traditional Chinese Medicine Database and Analysis Platform. HCC was used as a search query in GeneCards, Online Mendelian Inheritance in Man, Malacards, DisGeNET, Therapeutic Target Database, and Comparative Toxicogenomics Database. The overlapping targets of the Wuzhuyu decoction and HCC were defined, and then protein-protein interaction, Gene Ontology, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed. CytoHubba was used to select hub genes, and their binding activities and key active components were verified using molecular docking. RESULTS: A total of 764 compounds, 77 active compounds, and 204 potential target genes were identified in Wuzhuyu decoction. For HCC, 9468 potential therapeutic target genes were identified by combining the results from the six databases and removing duplicates. A total of 179 overlapping targets of Wuzhuyu decoction and HCC were defined, including 10 hub genes (tumor necrosis factor, interleukin-6, AKT1, TP53, caspase-3, mitogen-activated protein kinase 1, epidermal growth factor receptor, MYC, mitogen-activated protein kinase 8, and JUN). There were six main active components (quercetin, kaempferol, ginsenoside Rh2, rutaecarpine, ß-carotene, and ß-sitosterol) that may act on hub genes to treat HCC in Wuzhuyu decoction. Kyoto Encyclopedia of Genes and Genomes enrichment analysis mainly involved the mitogen-activated protein kinase, p53, phosphatidylinositol-4,5-bisphosphate 3-kinase-Akt, Janus kinase-signal transducer of activators of transcription, and Hippo signaling pathways. Further verification based on molecular docking results showed that the small molecule compounds (quercetin, kaempferol, ginsenoside Rh2, rutaecarpine, ß-carotene, and ß-sitosterol) contained in Wuzhuyu decoction generally have excellent binding affinity to the macromolecular target proteins encoded by the top 10 genes. CONCLUSION: This study revealed that Wuzhuyu decoction may be a latent multicomponent, multitarget, and multipathway treatment for HCC. It provided novel insights for verifying the mechanism of Wuzhuyu decoction in the treatment of HCC.

Single-Cell RNA Sequencing Analysis of the Heterogeneity in Gene Regulatory Networks in Colorectal Cancer.

Colorectal cancer (CRC) manifests as gastrointestinal tumors with high intratumoral heterogeneity. Recent studies have demonstrated that CRC may consist of tumor cells with different consensus molecular subtypes (CMS). The advancements in single-cell RNA sequencing have facilitated the development of gene regulatory networks to decode key regulators for specific cell types. Herein, we comprehensively analyzed the CMS of CRC patients by using single-cell RNA-sequencing data. CMS for all malignant cells were assigned using CMScaller. Gene set variation analysis showed pathway activity differences consistent with those reported in previous studies. Cell-cell communication analysis confirmed that CMS1 was more closely related to immune cells, and that monocytes and macrophages play dominant roles in the CRC tumor microenvironment. On the basis of the constructed gene regulation networks (GRNs) for each subtype, we identified that the critical transcription factor ERG is universally activated and upregulated in all CMS in comparison with normal cells, and that it performed diverse roles by regulating the expression of different downstream genes. In summary, molecular subtyping of single-cell RNA-sequencing data for colorectal cancer could elucidate the heterogeneity in gene regulatory networks and identify critical regulators of CRC.

Tribbles pseudokinase 3 (TRIB3) contributes to the progression of hepatocellular carcinoma by activating the mitogen-activated protein kinase pathway.

BACKGROUND: Tribble pseudokinase 3 (TRIB3) plays a key role in regulating the malignancy of many tumors. This study examined its function in cancer cells and explored the potential mechanisms of action. METHODS: The expression of TRIB3 was examined in hepatocellular carcinomas (HCCs) using The Cancer Genome Atlas (TCGA) database. A TRIB3 lentivirus with a flag label was constructed and transfected into Huh7 and Hep3B human hepatoma cell lines to generate cells that stably overexpress TRIB3. A small interfering RNA (siRNA) was designed to knockdown TRIB3 mRNA in HepG2 and Huh7. Cell viability and cell colony formation assays were conducted. Flow cytometry was performed to assess the cell cycle in cells overexpressing TRIB3. Western blotting were performed to examine the expression of (Mitogen-activated protein kinase, MAPKK) (MEK), phosphorylated-MEK (p-MEK), extracellular signal-regulated kinase (ERK), and p-MEK in cells with TRIB3 knockdown. The correlation between TRIB3 and SMARCD3 was assessed using co-immunoprecipitation assays and immunofluorescence. RESULTS: TRIB3 was significantly overexpressed in advanced grade HCC tissues and was closely correlated with poor prognosis. TRIB3 overexpression promoted the cell growth and cell cycle but had little effect on migration capabilities in Huh7 and Hep3B cells. Conversely, knockdown of TRIB3 had slow down the cell growth in Huh7 and HepG2 cells detected by CCK8 and colony formation assay. The expression of MEK and ERK at both the protein and mRNA levels were downregulated when TRIB3 was knocked down. The protein expression of p-ERK and p-MEK were also downregulated upon TRIB3 silencing. SMARCD3 is a transcript factor that is belongs to the SWI/SNF complex and has been shown to regulate many genes. Indeed, co-immunoprecipitation assays demonstrated that TRIB3 interacts with SMARCD3 in the nucleus, suggesting that it may regulate TRIB3 in HCCs. CONCLUSIONS: This study demonstrated that TRIB3 promotes the malignancy of HCC cells and its expression may be a potential diagnostic biomarker for HCC progression.

Facile one-pot synthesis, antiproliferative evaluation and structure-activity relationships of 3-amino-1H-indoles and 3-amino-1H-7-azaindoles.

A highly efficient method has been developed for the one-pot synthesis of substituted 3-amino-1H-indole and 3-amino-1H-7-azaindole derivatives starting from ethyl 2-cyanophenylcarbamate/ethyl 3-cyanopyridin-2-ylcarbamate, and α-bromoketones in good to excellent yields. All newly synthesized analogues were screened for their antiproliferative activities against four cancer cell lines. The most promising compound 8v demonstrated 13-, 5-, and 1.4-fold improvement compared to fluorouracil in inhibiting HeLa, HepG2, and MCF-7 cell proliferation with IC50 values of 3.7, 8.0, and 19.9 µM, respectively. Furthermore, 8v induced significant cell cycle arrest at the G2/M phase in HeLa cell lines via a concentration-dependent manner. These encouraging findings indicate that the common 3-amino-1H-7-azaindole is a very favorable scaffold for the design of novel anticancer small-molecule drugs.

Design, synthesis and antiproliferative activity of novel substituted 2-amino-7,8-dihydropteridin-6(5H)-one derivatives.

Based on our previous work, a series of novel 2-amino-7,8-dihydropteridin-6(5H)-one derivatives were designed and synthesized via a ring-closing strategy. Biological evaluation with four human cancer cell lines (BT549, T47D, MDA-MB-468, and MDA-MB-231) showed that most of these compounds possessed moderate to potent antiproliferative activities. The most promising compound 8-benzyl-2-(phenethylamino)-7,8-dihydropteridin-6(5H)-one (6q) possessing IC50 values of 7.75, 6.37, and 10.73µM against MDA-MB-468, T47D, and BT549, respectively, which were 49, 11, and 8 folds more active than the positive control fluorouracil. Moreover, fluorescence-activated cell sorting analysis revealed that compound 6q displayed a significant effect on G1 cell-cycle arrest in a concentration-dependent manner in T47D cells. The initial structure-activity relationship studies indicated that linker-length of amine chain in C-2 position of pyrimidine ring played a crucial role in modulating the antitumor activity, which could be of help in the rational design of dihydropteridin-6(5H)-ones as novel anticancer drugs.

Design, synthesis, and biological evaluation of novel alkylsulfanyl-1,2,4-triazoles as cis-restricted combretastatin A-4 analogues.

Thirty-two novel 3-alkylsulfanyl-1,2,4-triazole derivatives, designed as cis-restricted combretastatin A-4 analogues, were synthesized and evaluated for their antiproliferative activities. The results indicated that analogue 20 showed more potent antiproliferative activities against PC-3 cell lines than positive control CA-4. Particularly, the most promising compound 25 displayed 5-fold improvement compared to CA-4 in inhibiting HCT116 cell proliferation with IC50 values of 1.15 µM. Further flow-activated cell sorting analysis revealed that compound 20 displayed a significant effect on G2/M cell-cycle arrest in a dose-dependent manner in PC-3 cells. From this study, analogues 20 and 25 were the most potent anti-cancer agents in this structural class, and were considered lead compounds for further development as anti-cancer drugs.

Design, synthesis and antiproliferative activity of novel 5-nitropyrimidine-2,4-diamine derivatives bearing alkyl acetate moiety.

In order to discover new anticancer drug leads, a series of novel alkylamino pyrimidine derivatives were designed and synthesized based on our previous work via a ring-opening strategy. Biological evaluation with four human cancer cell lines (MDA-MB-231, A549, HepG2, and MCF-7) showed that most of these compounds possessed moderate to potent antiproliferative activities. The most promising compound 7w displayed a three-fold improvement compared with commercial anticancer drug fluorouracil in inhibiting HepG2 cell proliferation with IC50 value of 10.37 µM. Moreover, flow-activated cell sorting analysis suggested that compound 7w mainly arrested HepG2 cells in G2/M stage. Hence, it could serve as a promising lead for the design of novel anticancer small-molecule drugs.

Design, Synthesis and Molecular Docking Studies of Novel Indole-Pyrimidine Hybrids as Tubulin Polymerization Inhibitors.

A series of novel hybrids of indole-pyrimidine-containing piperazine moiety were designed, synthesized and evaluated for their antiproliferative and tubulin polymerization inhibitory activities. The results indicated that most of these compounds possessed significant cytotoxic potency against four cancer cell lines, HT-29, A549, MDA-MB-231 and MCF-7. Particularly, the most promising compound 34 showed more potent and broad-spectrum cytotoxic activities with the IC50 values ranged from 5.01 to 14.36 µm against A549, MDA-MB-231 and MCF-7 cell lines. Meanwhile, 34 also displayed the most potent tubulin polymerization inhibitory activity with IC50 value of 11.2 µm. Furthermore, molecular docking analysis demonstrated 34 interacts and binds efficiently with the tubulin protein at the colchicine-binding site. It was worth noting that the compound did not affect the normal human embryonic kidney cells, HEK-293. These results suggest that this novel class of indole-pyrimidine hybrids may have potential to be developed as new a class of tubulin polymerization inhibitors.

One-pot synthesis and antiproliferative activity of novel 2,4-diaminopyrimidine derivatives bearing piperidine and piperazine moieties.

A series of novel 2,4-diaminopyrimidines containing piperidine and piperazine moieties were synthesized via an efficient one-pot methodology. The bioassay tests demonstrated that compounds 27 and 28 displayed much stronger antitumor activities against four human cancer cell lines (HepG2, A549, MDA-MB-231 and MCF-7) than positive control fluorouracil. Particularly, compound 28 showed a two-fold improvement compared to fluorouracil in inhibiting MDA-MB-231 and A549 cell proliferation with IC50 values of 7.46 and 12.78 µM, respectively. Further flow-activated cell sorting analysis revealed that the most promising compound 28 displayed a significant effect on G2/M cell-cycle arrest in a dose-dependent manner in MDA-MB-231 cells.

Synthesis and cytotoxicity of 3,4-disubstituted-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazoles and novel 5,6-dihydro-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole derivatives bearing 3,4,5-trimethoxyphenyl moiety.

A series of 3,4-disubstituted-5-(3,4,5-trimethoxyphenyl)-4H-1,2,4-triazoles and some novel 5,6-dihydro-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles bearing 3,4,5-trimethoxyphenyl moiety were synthesized and screened for their anticancer activity. The preliminary bioassay results indicated that compounds 14 and 16 showed much stronger cytotoxicity than Doxorubicin against HepG2 cell lines with IC(50) values of 0.58 and 3.17 µM, respectively. Meanwhile compound 16 also exhibited a broad spectrum of antitumor activity against MCF-7 and MKN45 with IC(50) values of 10.92 and 13.79 µM, respectively.