T cell-related ubiquitination genes as prognostic indicators in hepatocellular carcinoma.

Background: T lymphocytes, integral to the adaptive immune system, wield pivotal influence in bolstering anti-tumor responses, and are strictly regulated by ubiquitination modification. The objective of this investigation was to devise a novel prognostic and immunotherapeutic efficacy predictor for hepatocellular carcinoma patients utilizing T cell-related ubiquitination genes (TCRUG). Method: The single-cell RNA sequencing (scRNA-seq) data and bulk RNA data of HCC patients are derived from the GEO database and TCGA database. Based on the processing of scRNA-seq, T cell marker genes are obtained and TCRUG is obtained. Further combined with WGCNA, differential analysis, univariate Cox regression analysis, LASSO analysis, and multivariate Cox regression analysis to filter and screen TCRUG. Finally construct a riskscore for predicting the prognosis of HCC patients, the predictive effect of which is validated in the GEO dataset. In addition, we also studied the correlation between riskscore and immunotherapy efficacy. Finally, the oncogenic role of UBE2E1 in HCC was explored through various in vitro experiments. Result: Based on patients' scRNA-seq data, we finally obtained 3050 T cell marker genes. Combined with bulk RNA data and clinical data from the TCGA database, we constructed a riskscore that accurately predicts the prognosis of HCC patients. This riskscore is an independent prognostic factor for HCC and is used to construct a convenient column chart. In addition, we found that the high-risk group is more suitable for immunotherapy. Finally, the proliferation, migration, and invasion abilities of HCC cells significantly decreased after UBE2E1 expression reduction. Conclusion: This study developed a riskscore based on TCRUG that can accurately and stably predict the prognosis of HCC patients. This riskscore is also effective in predicting the immune therapy response of HCC patients.

Small Molecule MIF Modulation Enhances Ferroptosis by Impairing DNA Repair Mechanisms.

Ferroptosis is a form of regulated cell death that can be modulated by small molecules and has the potential for the development of therapeutics for oncology. Although excessive lipid peroxidation is the defining hallmark of ferroptosis, DNA damage may also play a significant role. In this study, a potential mechanistic role for MIF in homologous recombination (HR) DNA repair is identified. The inhibition or genetic depletion of MIF or other HR proteins, such as breast cancer type 1 susceptibility protein (BRCA1), is demonstrated to significantly enhance the sensitivity of cells to ferroptosis. The interference with HR results in the translocation of the tumor suppressor protein p53 to the mitochondria, which in turn stimulates the production of reactive oxygen species. Taken together, the findings demonstrate that MIF-directed small molecules enhance ferroptosis via a putative MIF-BRCA1-RAD51 axis in HR, which causes resistance to ferroptosis. This suggests a potential novel druggable route to enhance ferroptosis by targeted anticancer therapeutics in the future.

Discovery of Novel Fedratinib-Based HDAC/JAK/BRD4 Triple Inhibitors with Remarkable Antitumor Activity against Triple Negative Breast Cancer.

Multitarget HDAC inhibitors capable of simultaneously blocking the BRD4-LIFR-JAK1-STAT3 signaling pathway hold great potential for the treatment of TNBC and other solid tumors. Herein, novel Fedratinib-based multitarget HDAC inhibitors were rationally designed, synthesized, and biologically evaluated, among which compound 25ap stood out as a potent HDAC/JAK/BRD4 triple inhibitor. Satisfyingly, compound 25ap led to concurrent inhibition of HDACs and the BRD4-LIFR-JAK1-STAT3 signaling pathway, which was validated by hyper-acetylation of histone and α-tubulin, hypo-phosphorylation of STAT3, downregulation of LIFR, MCL-1, and c-Myc in MDA-MB-231 cells. The multitarget effects of 25ap contributed to its robust antitumor response, including potent antiproliferative activity, remarkable apoptosis-inducing activity, and inhibition of colony formation. Notably, 25ap possessed an acceptable therapeutic window between normal and cancerous cells, desirable in vitro metabolic stability in mouse microsome, and sufficient in vivo exposure via intraperitoneal administration. Additionally, the in vivo antitumor potency of 25ap was demonstrated in an MDA-MB-231 xenograft model.

Laparoscopic versus Open Inguinal Hernia Repair in Aging Patients: A Propensity Score Matching-Based Retrospective Study.

Objective: Although laparoscopic repair has been widely carried out and promoted due to its minimally invasive advantages, open surgery is still popular compared to elderly patients. This study aims to compare the outcomes of laparoscopic (LIHR) vs open repair of inguinal hernias (OIHR) in elderly patients. Methods: A retrospective analysis of the database was performed to identify elderly patients, from January 2021 through December 2022, who underwent surgery for an inguinal hernia. After a 1:1 propensity score matching (PSM) with a caliper of 0.1 was conducted to balance potential bias, binary logistic regressions were used for categorical and continuous outcomes. Results: After PSM, 78 pairs of elderly patients were enrolled in this study, and there were no significant differences in baseline between LIHR and OIHR groups. Compared to OIHR, univariable and multivariable logistic regression analysis showed that LIHR was independently affected for reducing intraoperative hemorrhage (OR = 0.06, 95% CI: 0.02-0.18, P < 0.001) and shortening postoperative hospitalization time (OR = 0.29, 95% CI: 0.15-0.57, P < 0.001) in elderly patients. Furthermore, LIHR (OR = 0.28, 95% CI: 0.14-0.57, P < 0.001) and age (OR = 0.89, 95% CI: 0.82-0.96, P = 0.002) were independent affecting factors for relieving postoperative pain. Meanwhile, no obvious differences were detected in postoperative complications [LIHR 7.7% (6/78) vs OIHR 14.1% (11/78), P = 0.199]. Conclusion: LIHR was closely associated with reducing intraoperative hemorrhage and shortening postoperative hospitalization time. Whilst LIHR and age were independently affecting factors for relieving postoperative pain.

Discovery of the First Irreversible HDAC6 Isoform Selective Inhibitor with Potent Anti-Multiple Myeloma Activity.

In our previous research, a series of phenylsulfonylfuroxan-based hydroxamates were developed, among which compound 1 exhibited remarkable in vitro and in vivo antitumor potency due to its histone deacetylase (HDAC) inhibitory and nitric oxide (NO)-donating activities. Herein, the in-depth study of compound 1 revealed that this HDAC inhibitor-NO donor hybrid could enduringly increase the intracellular levels of acetyl histones and acetyl α-tubulin, which could be ascribed to its irreversible inhibition toward class I HDACs and HDAC6. Structural modification of compound 1 led to a novel phenylsulfonylfuroxan-based hydroxamate 4, which exhibited considerable HDAC6 inhibitory activity and selectivity. Furthermore, compound 4 could inhibit intracellular HDAC6 both selectively and irreversibly. To the best of our knowledge, this is the first research reporting the irreversible inhibition of HDAC6. It was also demonstrated that compared with ACY-241 (a reversible HDAC6 inhibitor in clinical trials), the irreversible HDAC6 selective inhibitor 4 exhibited not only superior anti-multiple myeloma activity but also improved therapeutic index.

Discovery of highly potent HDAC8 PROTACs with anti-tumor activity.

Various diseases are deeply associated with aberrations in HDAC8 functions. These aberrations can be assigned to either structural functions or catalytic functions of HDAC8. Therefore, development of HDAC8 degradation inducers might be more promising than HDAC8 inhibitors. We employed the proteolysis targeting chimera (PROTAC) strategy to develop a selective and potent HDAC8 degradation inducer CT-4 with single-digit nanomolar DC50 values and over 95% Dmax in both triple-negative breast cancer MDA-MB-231 cells and T-cell leukemia cells. Notably, CT-4 demonstrated potent anti-migration activity and limited anti-proliferative activity in MDA-MB-231 cells. In contrast, CT-4 effectively induced apototic cell death in Jurkat cells, as assessed by a caspase 3/7 activity assay and flow cytometry. Our findings suggest that the development of HDAC8 degradation inducers holds great potential for the treatment of HDAC8-related diseases.

HDAC/MIF dual inhibitor inhibits NSCLC cell survival and proliferation by blocking the AKT pathway.

Non-small-cell lung carcinoma (NSCLC) is one of the most common forms of lung cancer, and a leading cause of cancer death among human beings. There is an urgent demand for novel therapeutics for the treatment of NSCLC to enhance the efficacy of the currently applied Tyrosine kinase inhibitors (TKIs) therapy and to overcome therapy-resistance. Here, we report a novel small-molecule inhibitor that simultaneously targets histone deacetylase (HDAC) and macrophage migration inhibitory factor (MIF). The HDAC/MIF dual inhibitor proved to be toxic for EGFR mutated (H1650, TKI-resistant) or knock out (A549 EGFR-/-) NSCLC cell lines. Further experiments showed that HDAC inhibition inhibits cell survival and proliferation, while MIF inhibition downregulates pAKT or AKT expression level, which both interfere with cell survival. Furthermore, the combination treatment of TKI and HDAC/MIF dual inhibitor showed that the dual inhibitor enhanced TKI inhibitory efficacy, highlighting the advantages of HDAC/MIF dual inhibitor for more effective treatment of NSCLC.

Development of selective HDAC6 inhibitors with in vitro and in vivo anti-multiple myeloma activity.

Histone deacetylase 6 (HDAC6) is a promising therapeutic target for the treatment of cancers, neurodegenerative diseases and autoimmune disorders. Herein a novel series of pyrrolo[2,3-d]pyrimidine-based HDAC inhibitors were designed, synthesized and biologically evaluated, among which compounds 7a, 12a1, and 16a1 exhibited potent inhibitory activities and selectivities against HDAC6. Notably, compared with the well-known HDAC6 inhibitor Tubastatin A, our pyrrolo[2,3-d]pyrimidine-based HDAC6 inhibitors showed superior in vitro antiproliferative activity against human multiple myeloma cell lines RPMI 8226, U266 and MM.1S, while maintaining the low cytotoxicity against human breast cancer cell line MDA-MB-231 and two normal cell lines. The HDAC6 selective inhibition of one representative compound 12a1 in RPMI 8226 cells was confirmed by western blot analysis. Although pyrrolo[2,3-d]pyrimidine is a privileged structure in many kinase inhibitors, compound 12a1 showed negligible inhibition against several kinases including JAK family members and Akt1, indicating its acceptable off-target profile. Besides, compound 12a1 exhibited desirable metabolic stability in mouse liver microsome. The in vivo anti-multiple myeloma potency of 12a1, alone and in combination with bortezomib, was demonstrated in a RPMI 8226 xenograft model.

Development of pyrazoline-based derivatives as aminopeptidase N inhibitors to overcome cancer invasion and metastasis.

Aminopeptidase N is considered as a promising anti-tumor target due to its role in tumor invasion, metastasis and angiogenesis. In this report, a new series of pyrazoline-based derivatives were designed, synthesized and evaluated for biological activities. The structure-activity relationships of these pyrazoline-based derivatives were also discussed in detail. Among them, compound 2k, with 2,6-dichloro substitution, showed the best APN inhibitory activity, of which the IC50 value was two orders of magnitude lower than that of the positive control bestatin. At the same concentration of 100 µM, the in vitro anti-invasion activity of compound 2k was also significantly better than that of bestatin. Moreover, compound 2k could effectively prevent the pulmonary metastasis of mice H22 hepatoma cells in vivo, supporting its further research and development as an antitumor agent.

Development of a Bestatin-SAHA Hybrid with Dual Inhibitory Activity against APN and HDAC.

With five histone deacetylase (HDAC) inhibitors approved for cancer treatment, proteolysis-targeting chimeras (PROTACs) for degradation of HDAC are emerging as an alternative strategy for HDAC-targeted therapeutic intervention. Herein, three bestatin-based hydroxamic acids (P1, P2 and P3) were designed, synthesized and biologically evaluated to see if they could work as HDAC degrader by recruiting cellular inhibitor of apoptosis protein 1 (cIAP1) E3 ubiquitin ligase. Among the three compounds, the bestatin-SAHA hybrid P1 exhibited comparable even more potent inhibitory activity against HDAC1, HDAC6 and HDAC8 relative to the approved HDAC inhibitor SAHA. It is worth noting that although P1 could not lead to intracellular HDAC degradation after 6 h of treatment, it could dramatically decrease the intracellular levels of HDAC1, HDAC6 and HDAC8 after 24 h of treatment. Intriguingly, the similar phenomenon was also observed in the HDAC inhibitor SAHA. Cotreatment with proteasome inhibitor bortezomib could not reverse the HDAC decreasing effects of P1 and SAHA, confirming that their HDAC decreasing effects were not due to protein degradation. Moreover, all three bestatin-based hydroxamic acids P1, P2 and P3 exhibited more potent aminopeptidase N (APN, CD13) inhibitory activities than the approved APN inhibitor bestatin, which translated to their superior anti-angiogenic activities. Taken together, a novel bestatin-SAHA hybrid was developed, which worked as a potent APN and HDAC dual inhibitor instead of a PROTAC.

Synthesis and biological study of class I selective HDAC inhibitors with NO releasing activity.

Based on the multi-mechanism antitumor strategy and the regulatory effect of nitric oxide (NO) on histone deacetylases (HDACs), a series of N-acyl-o-phenylenediamine-based HDAC inhibitors equipped with the phenylsulfonylfuroxan module as NO donor was designed, synthesized and biologically evaluated. The in vitro HDAC inhibitory assays revealed that compared with the clinical class I selective HDAC inhibitor MS275, compounds 7c, 7d and 7e possessed similar HDAC inhibitory potency and selective profile, which were confirmed by the results of western blot analysis. The western blot analysis also showed that NO scavenger N-acetyl cysteine (NAC) could weaken the intracellular HDAC inhibitory ability of compound 7c, supporting the HDAC inhibitory effect of NO generated by 7c. It is worth noting that compounds 7c, 7d and 7e exhibited more potent in vitro antiproliferative activities than MS275 against all four tested solid tumor cell lines. The promising in vivo antitumor potency of 7c was demonstrated in a HCT116 xenograft model.

MiR-4262 inhibits the development of esophageal cancer by negatively regulating KLF6 level.

OBJECTIVE: To uncover the expression pattern and the prognosis of miR-4262 in these patients with esophageal cancer, and its potential mechanism. METHODS: MiR-4262 levels in 57 esophageal cancer and paracancerous specimens were detected. The relationship between miR-4262 level and clinical features of esophageal cancer was analyzed. After overexpression of miR-4262 in OE19 and EC-109 cells, changes in proliferative potential and apoptosis were examined. The interaction between miR-4262 and KLF6 was explored by dual-luciferase reporter assay. Their involvement in the development of esophageal cancer was finally determined. RESULTS: MiR-4262 was downregulated in esophageal cancer specimens and cell lines. Low level of miR-4262 predicted advanced pathological staging and poor prognosis in esophageal cancer patients. Overexpression of miR-4262 reduced proliferative potential and enhanced apoptosis in esophageal cancer cells. KLF6 was the downstream gene binding to miR-4262. The interaction between miR-4262 and KLF6 was responsible for alleviating the malignant development of esophageal cancer. CONCLUSIONS: MiR-4262 is downregulated in esophageal cancer and linked to its pathological staging and prognosis. MiR-4262 inhibits the malignant development of esophageal cancer by down-regulating KLF6.

Histone deacetylase (HDAC) inhibitors in cancer: a patent review (2017-present).

Introduction: Histone deacetylase (HDAC) inhibitors play a crucial role in restoring the balance of acetylation and deacetylation of lysine residues of histones and non-histone proteins, which are applied to treat several diseases including cancer.Area covered: This review covers recent efforts in the synthesis and applications of inhibitors and hybrid inhibitors targeting HDAC from 2017 to 2019.Expert opinion: HDACs are important epigenetic targets and HDAC inhibitors have become important biologically active compounds for the treatment of cancers. Among the recent patents available, most of them place emphasis on HDAC selective inhibitors and multitarget HDAC inhibitors. Although great accomplishments have been achieved in developing HDAC selective inhibitors, there is still an urgent need for discovery of novel HDAC inhibitors with new zinc-binding groups avoiding the unfavorable pharmacokinetics profiles of hydroxamic acid. Apart from cancer therapy, HDAC inhibitors have recently been considered as a new strategy in treating other human diseases, such as alcohol use disorder (AUD), neurological disorders, age-related diseases, and so forth.

Design, Synthesis and Biological Evaluation of Novel Osimertinib-Based HDAC and EGFR Dual Inhibitors.

Herein a novel series of histone deacetylases (HDACs) and epidermal growth factor receptor (EGFR) dual inhibitors were designed and synthesized based on the structure of the approved EGFR inhibitor osimertinib (AZD9291). Among them, four compounds 5D, 5E, 9D and 9E exhibited more potent total HDAC inhibition than the approved HDAC inhibitor SAHA. However, these compounds only showed moderate to low inhibitory potency towards EGFR with compounds 5E and 9E possessing IC50 values against EGFRWT and EGFRT790M in the micromolar range. 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay revealed the potent antiproliferative activities of compounds 5D, 5E, 9D and 9E, among which 9E was even more potent against HeLa, MDA-MB-231, MDA-MB-468, HT-29 and KG-1 cell lines than SAHA and AZD9291. Further selectivity profile of 9E showed that this compound was not active against other 13 cancer-related kinases and two epigenetic targets lysine specific demethylase 1 (LSD1) and bromodomain-containing protein 4 (BRD4). These results support further structural modification of 9E to improve its EGFR inhibitory activity, which will lead to more potent and balanced HDAC and EGFR dual inhibitors as anticancer agents.

Leucine ureido derivatives as aminopeptidase N inhibitors using click chemistry. Part II.

Aminopeptidase N (APN) has been proved to be deeply associated with cancer angiogenesis, metastasis and invasion. Therefore, APN gains increasing attention as a promising anti-tumor target. In the current study, we report the design, synthesis, biological evaluation and structure-activity relationship of one new series of leucine ureido derivatives containing the 1,2,3-triazole moiety. Among them, compound 31f was identified as the best APN inhibitor with IC50 value being two orders of magnitude lower than that of the positive control bestatin. Compound 31f possessed selective cytotoxicity to several tumor cell lines over the normal cell line human umbilical vein endothelial cells (HUVECs). Notably, when combined with 5-fluorouracil (5-Fu), 31f exhibited synergistic anti-proliferation effect against several tumor cell lines. At the same concentration, 31f exhibited much better anti-angiogenesis activities than bestatin in the HUVECs capillary tube formation assay and the rat thoracic aorta rings test. In the in vitro anti-invasion assay, 31f also exhibited superior potency over bestatin. Moreover, considerable in vivo antitumor potencies of 31f alone or in combination with 5-Fu were observed without significant toxic signs in a mouse heptoma H22 tumor transplant model.

Novel leucine ureido derivatives as aminopeptidase N inhibitors using click chemistry.

The over-expression of aminopeptidase N on diverse malignant cells is associated with the tumor angiogenesis and metastasis. In this report, one new series of leucine ureido derivatives containing the triazole moiety was designed, synthesized and evaluated as APN inhibitors. Among them, compound 13v showed the best APN inhibition with an IC50 value of 0.089 ±â€¯0.007 µM, which was two orders of magnitude lower than that of bestatin (IC50 = 9.4 ±â€¯0.5 µM). Compound 13v also showed dose-dependent anti-angiogenesis activities. Even at the lower concentration (10 µM), compound 13v presented similar anti-angiogenesis activity compared with bestatin at 100 µM in both the human umbilical vein endothelial cells (HUVECs) capillary tube formation assay and the rat thoracic aorta rings test. Moreover, compared with bestatin, 13v exhibited comparable, if not better in vivo anti-metastasis activity in a mouse H22 pulmonary metastasis model.

Discovery of meta-sulfamoyl N-hydroxybenzamides as HDAC8 selective inhibitors.

In the past decade, although research and development of histone deacetylase (HDAC) inhibitors as therapeutic agents have achieved great accomplishments, especially in oncology field, there is still an urgent need for the discovery of isoform-selective HDAC inhibitors considering the side effects caused by nonselective HDAC inhibitors. HDAC8, a unique class I zinc-dependent HDAC, is becoming a potential target in cancer and other diseases. In the current study, a novel series of N-hydroxy-3-sulfamoylbenzamide-based HDAC8 selective inhibitors (12a-12p) were designed and synthesized, among which compounds 12a, 12b and 12c exhibited potent HDAC8 inhibition with two-digit nanomolar IC50 values, and considerable selectivity over HDAC2 (>180-fold) and HDAC6 (∼30-fold) which was confirmed by western blot analysis. It is worth noting that 12a, 12b and 12c displayed highly selective anti-proliferative activity to T-cell leukemia cell lines Jurkat, Molt-4 and neuroblastoma cell line SK-N-BE-(2). Such selective cytotoxicity was also observed in the well-known HDAC8 selective inhibitor PCI-34051 but not in the pan-HDAC inhibitors SAHA and PXD101, indicating that HDAC8 selective inhibitor should have preferable benefit-risk profile in comparison with pan-HDAC inhibitor. Finally, the HDAC8 selectivity of 12a, 12b and 12c was rationalized by molecular docking study.