Overcoming Mycobacterium tuberculosis through small molecule inhibitors to break down cell wall synthesis

Mycobacterium tuberculosis(MTB) utilizes multiple mechanisms to obtain antibiotic resistance during the treatment of infections. In addition, the biofilms, secreted by MTB, can further protect the latter from the contact with drug molecules and immune cells. These self-defending mechanisms lay a formidable challenge to develop effective therapeutic agents against chronic and recurring antibiotictolerant MTB infections. Although several inexpensive and effective drugs(isoniazid, rifampicin, pyrazinamide and ethambutol) have been discovered for the treatment regimen, MTB continues to cause considerable morbidity and mortality worldwide. Antibiotic resistance and tolerance remain major global issues, and innovative therapeutic strategies are urgently needed to address the challenges associated with pathogenic bacteria. Gratifyingly, the cell wall synthesis of tubercle bacilli requires the participation of many enzymes which exclusively exist in prokaryotic organisms. These enzymes, absent in human hepatocytes, are recognized as promising targets to develop anti-tuberculosis drug. In this paper, we discussed the critical roles of potential drug targets in regulating cell wall synthesis of MTB. And also, we systematically reviewed the advanced development of novel bioactive compounds or drug leads for inhibition of cell wall synthesis, including their discovery, chemical modification, in vitro and in vivo evaluation.

Inetetamab combined with pyrotinib and chemotherapy in the treatment of breast cancer brain metastasis: A case report

BACKGROUND Breast cancer brain metastasis(BCBM)is an advanced breast disease that is difficult to treat and is associated with a high risk of death.Patient prognosis is usually poor,with reduced quality of life.In this context,we report the case of a patient with HER-2-positive BCBM treated with a macromolecular mAb(ine-tetamab)combined with a small molecule tyrosine kinase inhibitor(TKI).CASE SUMMARY The patient was a 58-year-old woman with a 12-year history of type 2 diabetes.She was compliant with regular insulin treatment and had good blood glucose control.The patient was diagnosed with invasive carcinoma of the right breast(T3N1M0 stage IIIa,HER2-positive type)through aspiration biopsy of the ipsilateral breast due to the discovery of a breast tumor in February 2019.Immunohistochemistry showed ER(-),PR(-),HER-2(3+),and Ki-67(55-60%+).Preoperative neoadjuvant chemotherapy,i.e.,the AC-TH regimen(epirubicin,cyclophosphamide,docetaxel-paclitaxel,and trastuzumab),was administered for 8 cycles.She underwent modified radical mastectomy of the right breast in November 2019 and received tocilizumab targeted therapy for 1 year.Brain metastasis was found 9 mo after surgery.She underwent brain metastasectomy in August 2020.Immunohistochemistry showed ER(-)and PR.(-),HER-2(3+),and Ki-67(10-20%+).In November 2020,the patient experienced headache symptoms.After an examination,tumor recurrence in the original surgical region of the brain was observed,and the patient was treated with inetetamab,pyrotinib,and capecitabine.Whole-brain radiotherapy was recommended.The patient and her family refused radiotherapy for personal reasons.In September 2021,a routine examination revealed that the brain tumor was considerably larger.The original systemic treatment was continued and combined with intensity-modulated radiation therapy for brain metastases,followed by regular hospitalization and routine examinations.The patient’s condition is generally stable,and she has a relatively high quality of life.This case report demonstrates that in patients with BCBM and resistance to trastuzumab,inetetamab combined with pyrotinib and chemotherapy can prolong survival.CONCLUSION Inetetamab combined with small molecule TKI drugs,chemotherapy and radiation may be an effective regimen for maintaining stable disease in patients with BCBM.

Treatment of gastrointestinal neuroendocrine tumors with inhibitors of growth factor receptors and their signaling pathways: Recent advances and future perspectives

The limited efficacy of conventional cytotoxic treatment regimes for advanced gastrointestinal neuroendocrine cancers emphasizes the need for novel and more effective medical treatment options. Recent findings on the specific biological features of this family of neoplasms has led to the development of new targeted therapies, which take into account the high vascularization and abundant expression of specific growth factors and cognate tyrosine kinase receptors. This review will briefly summarize the status and future perspectives of antiangiogenic, mTOR- or growth factor receptor-based pharmacological approaches for the innovative treatment of gastrointestinal neuroendocrine tumors. In view of the multitude of novel targeted approaches, the rationale for innovative combination therapies, i.e. combining growth factor (receptor)-targeting agents with chemo- or biotherapeutics or with other novel anticancer drugs such as HDAC or proteasome inhibitors will be taken into account.

Therapeutic strategies of glioblastoma (GBM):The current advances in the molecular targets and bioactive small molecule compounds

Glioblastoma(GBM)is the most common aggressive malignant tumor in brain neuroepithelial tumors and remains incurable.A variety of treatment options are currently being explored to improve patient survival,including small molecule inhibitors,viral therapies,cancer vaccines,and monoclonal antibodies.Among them,the unique advantages of small molecule inhibitors have made them a focus of attention in the drug discovery of glioblastoma.Currently,the most used chemotherapeutic agents are small molecule inhibitors that target key dysregulated signaling pathways in glioblastoma,including receptor tyrosine kinase,PI3K/AKT/mTOR pathway,DNA damage response,TP53 and cell cycle inhibitors.This review analyzes the therapeutic benefit and clinical development of novel small molecule inhibitors discovered as promising anti-glioblastoma agents by the related targets of these major pathways.Meanwhile,the recent advances in temozolomide resistance and drug combination are also reviewed.In the last part,due to the constant clinical failure of targeted therapies,this paper reviewed the research progress of other therapeutic methods for glioblastoma,to provide patients and readers with a more comprehensive understanding of the treatment landscape of glioblastoma.

Modulation of protein fate decision by small molecules:targeting molecular chaperone machinery

Modulation of protein fate decision and protein homeostasis plays a significant role in altering the protein level,which acts as an orientation to develop drugs with new mechanisms.The molecular chaperones exert significant biological functions on modulation of protein fate decision and protein homeostasis under constantly changing environmental conditions through extensive protein-protein interactions(PPIs)with their client proteins.With the help of molecular chaperone machinery the processes of protein folding,trafficking,quality control and degradation of client proteins could be arranged properly.The core members of molecular chaperones,including heat shock proteins(HSPs)family and their co-chaperones,are emerging as potential drug targets since they are involved in numerous disease conditions.Development of small molecule modulators targeting not only chaperones themselves but also the PPIs among chaperones,co-chaperones and clients is attracting more and more attention.These modulators are widely used as chemical tools to study chaperone networks as well as potential drug candidates for a broader set of diseases.Here,we reviewed the key checkpoints of molecular chaperone machinery HSPs as well as their co-chaperones to discuss the small molecules targeting on them for modulation of protein fate decision.

Growth factor receptors and related signalling pathways as targets for novel treatment strategies of hepatocellular cancer

Growth factors and their corresponding receptors are commonly overexpressed and/or dysregulated in many cancers including hepatocellular cancer （HCC）. Clinical trials indicate that growth factor receptors and their related signalling pathways play important roles in HCC cancer etiology and progression, thus providing rational targets for innovative cancer therapies. A number of strategies including monoclonal antibodies, tyrosine kinase inhibitors （＂small molecule inhibitors＂） and antisense oligonucleotides have already been evaluated for their potency to inhibit the activity and downstream signalling cascades of these receptors in HCC. First clinical trials have also shown that multi-kinase inhibition is an effective novel treatment strategy in HCC. In this respect sorafenib, an inhibitor of Raf-, VEGF- and PDGF-signalling, is the first multi-kinase inhibitor that has been approved by the FDA for the treatment of advanced HCC. Moreover, the serine-threonine kinase of mammalian target of rapamycin （mTOR） upon which the signalling of several growth factor receptors converge plays a central role in cancer cell proliferation, roTOR inhibition of HCC is currently also being studied in preclinical trials. As HCCs represent hypervascularized neoplasms, inhibition of tumour vessel formation via interfering with the VEGF/VEGFR system is another promising approach in HCC treatment. This review will summarize the current status of the various growth factor receptor-based treatment strategies and in view of the multitude of novel targeted approaches, the rationale for combination therapies for advanced HCC treatment will also be taken into account.

Discovery of a small molecule inhibitor of cullin neddylation that triggers ER stress to induce autophagy

Protein neddylation is catalyzed by a three-enzyme cascade,namely an E1 NEDD8-activating enzyme(NAE),one of two E2 NEDD8 conjugation enzymes and one of several E3 NEDD8 ligases.The physiological substrates of neddylation are the family members of cullin,the scaffold component of cullin RING ligases(CRLs).Currently,a potent E1 inhibitor,MLN4924,also known as pevonedistat,is in several clinical trials for anti-cancer therapy.Here we report the discovery,through virtual screening and structural modifications,of a small molecule compound HA-1141 that directly binds to NAE in both in vitro and in vivo assays and effectively inhibits neddylation of cullins 1 e5.Surprisingly,unlike MLN4924,HA-1141 also triggers non-canonical endoplasmic reticulum(ER)stress and PKR-mediated terminal integrated stress response(ISR)to activate ATF4 at an early stage,and to inhibit protein synthesis and mTORC1 activity at a later stage,eventually leading to autophagy induction.Biologically,HA-1141 suppresses growth and survival of cultured lung cancer cells and tumor growth in in vivo xenograft lung cancer models at a well-tolerated dose.Taken together,our study has identified a small molecule compound with the dual activities of blocking neddylation and triggering ER stress,leading to growth suppression of cancer cells.

Targeted medical therapy of biliary tract cancer:Recent advances and future perspectives

The limited efficacy of cytotoxic therapy for advanced biliary tract and gallbladder cancers emphasizes the need for novel and more effective medical treatment options. A better understanding of the specific biological features of these neoplasms led to the development of new targeted therapies, which take the abundant expression of several growth factors and cognate tyrosine kinase receptors into account. This review will briefly summarize the status and future perspectives of antiangiogenic and growth factor receptor-based pharmacological approaches for the treatment of biliary tract and gallbladder cancers. In view of multiple novel targeted approaches, the rationale for innovative therapies, such as combinations of growth factor (receptor)-targeting agents with cytotoxic drugs or with other novel anticancer drugs will be highlighted.

Targeting PP2A for cancer therapeutic modulation

Protein phosphatases play essential roles as negative regulators of kinases and signaling cascades involved in cytoskeletal organization.Protein phosphatase 2A(PP2A)is highly conserved and is the predominant serine/threonine phosphatase in the nervous system,constituting more than 70%of all neuronal phosphatases.PP2A is involved in diverse regulatory functions,including cell cycle progression,apoptosis,and DNA repair.Although PP2A has historically been identified as a tumor suppressor,inhibition of PP2A has paradoxically demonstrated potential as a therapeutic target for various cancers.LB100,a water-soluble,small-molecule competitive inhibitor of PP2A,has shown particular promise as a chemo-and radio-sensitizing agent.Preclinical success has led to a profusion of clinical trials on LB100 adjuvant therapies,including a phase I trial in extensive-stage small-cell lung cancer,a phase I/II trial in myelodysplastic syndrome,a phase II trial in recurrent glioblastoma,and a completed phase I trial assessing the safety of LB100 and docetaxel in various relapsed solid tumors.Herein,we review the development of LB100,the role of PP2A in cancer biology,and recent advances in targeting PP2A inhibition in immunotherapy.

A small molecule inhibitor targeting SHP2 mutations for the lung carcinoma

The RAS/mitogen-activated protein kinase(MAPK)pathway disorder induced by the missense mutations in the tyrosine-protein phosphatase non-receptor type 11(PTPN11)gene which resulted in the nonreceptor protein tyrosine phosphatase SHP2 dysfunction has been reported in many lung cancer cases.Moreover,the Src homology region 2(SH2)-containing protein tyrosine phosphatase 2(SHP2)mutation or deletion triggers multiple signaling pathway dysfunctions including RAS/MAPK,RAS/extracellular-signal-regulated kinase(ERK),phosphatidylinositol 3-kinase(PI3K)/protein kinase B(AKT),Janus kinase/signal transducers and activators of transcription(JAK/STAT)and Hippo/yes-associated protein(YAP)which affect the expression of growth factors,cytokines and hormones.In recent years,the developing of the small molecule SHP2 inhibitors received a lot of attention.In this review,we summarize the recent years'progresses of the SHP2 inhibitors development for the lung cancer treatment.

Stress-activated kinases as therapeutic targets in pancreatic cancer

Pancreatic cancer is a dismal disease with high incidence and poor survival rates.With the aim to improve overall survival of pancreatic cancer patients,new therapeutic approaches are urgently needed.Protein kinases are key regulatory players in basically all stages of development,maintaining physiologic functions but also being involved in pathogenic processes.c-Jun N-terminal kinases(JNK)and p38 kinases,representatives of the mitogen-activated protein kinases,as well as the casein kinase 1(CK1)family of protein kinases are important mediators of adequate response to cellular stress following inflammatory and metabolic stressors,DNA damage,and others.In their physiologic roles,they are responsible for the regulation of cell cycle progression,cell proliferation and differentiation,and apoptosis.Dysregulation of the underlying pathways consequently has been identified in various cancer types,including pancreatic cancer.Pharmacological targeting of those pathways has been the field of interest for several years.While success in earlier studies was limited due to lacking specificity and off-target effects,more recent improvements in small molecule inhibitor design against stress-activated protein kinases and their use in combination therapies have shown promising in vitro results.Consequently,targeting of JNK,p38,and CK1 protein kinase family members may actually be of particular interest in the field of precision medicine in patients with highly deregulated kinase pathways related to these kinases.However,further studies are warranted,especially involving in vivo investigation and clinical trials,in order to advance inhibition of stress-activated kinases to the field of translational medicine.

Mechanism Study of the Kidney Renal Papillary Cell Carcinoma Proliferation Inhibition and Apoptosis Induction by EZH2

EZH2 is an important target in a variety of tumors, but its role in KIRP (Kidney renal papillary cell carcinoma) has not yet been proven. The aim of this study was to investigate the role of EZH2 in KIRP patients. And to investigate the KIRP, we used two KIRP cell lines, SKRC39 and ACHN in this study. We used CCK8 assay and colony formation assay to study the effect of EHZ2 small molecule inhibitor EPZ6438 on cancer cell proliferation, we used Trypan Blue cell counting experiments to study the effect of EZH2 on cancer cell apoptosis, and we also used qRT-PCR to study the mechanism of EZH2 on cancer cell proliferation. The results showed that EZH2 was elevated in KIRP patients;inhibition of EZH2 could inhibit the proliferation of cancer cells and induce the apoptosis of cancer cells, which is valuable for the control of KIRP in patients. As for the mechanism, we found that inhibition of EZH2 upregulated P53 expression and thus activated this tumor suppressor gene, indicating why EHZ1 inhibits renal cancer cells.

Drug discovery of sclerostin inhibitors

Sclerostin, a protein secreted from osteocytes, negatively regulates the WNT signaling pathway by binding to the LRP5/6 co-receptors and further inhibits bone formation and promotes bone resorption. Sclerostin contributes to musculoskeletal system-related diseases, making it a promising therapeutic target for the treatment of WNT-related bone diseases. Additionally, emerging evidence indicates that sclerostin contributes to the development of cancers, obesity, and diabetes, suggesting that it may be a promising therapeutic target for these diseases. Notably, cardiovascular diseases are related to the protective role of sclerostin. In this review, we summarize three distinct types of inhibitors targeting sclerostin, monoclonal antibodies, aptamers, and small-molecule inhibitors, from which monoclonal antibodies have been developed. As the first-in-class sclerostin inhibitor approved by the U.S. FDA,the monoclonal antibody romosozumab has demonstrated excellent effectiveness in the treatment of postmenopausal osteoporosis;however, it conferred high cardiovascular risk in clinical trials. Furthermore,romosozumab could only be administered by injection, which may cause compliance issues for patients who prefer oral therapy. Considering these above safety and compliance concerns, we therefore present relevant discussion and offer perspectives on the development of next-generation sclerostin inhibitors by following several ways, such as concomitant medication, artificial intelligence-based strategy, druggable modification, and bispecific inhibitors strategy.

Therapeutic potential of TNFa inhibitors in chronic inflammatory disorders:Past and future

In the past 20 years,patients with rheumatoid arthritis(RA),Crohn’s disease(CD),and other immune diseases have witnessed the impact of a great treatment advance with the availability of biological TNFa inhibitors.With 5 approved anti-TNFa biologics on the market and soon available biosimilars,patients have more treatment options and have benefited from understanding the biology of TNFa.Nevertheless,many unmet needs remain for people living with TNFa-related diseases,namely some side effects and tolerance of current anti-TNFa biologics and resistance to therapies.Furthermore,common diseases such as osteoarthritis and back/neck pain may respond to anti-TNFa therapies at early onset of symptoms.Development of new TNFa inhibitors focusing on TNFR1 specific inhibitors,preferably small molecules that can be delivered orally,is much needed.

New insight into targeting the DNA damage response in the treatment of glioblastoma

Glioblastoma(GBM)is the most common invasive malignant tumor in human brain tumors,representing the most severe grade of gliomas.Despite existing therapeutic approaches,patient prognosis remains dismal,necessitating the exploration of novel strategies to enhance treatment efficacy and extend survival.Due to the restrictive nature of the blood-brain barrier(BBB),smallmolecule inhibitors are prioritized in the treatment of central nervous system tumors.Among these,DNA damage response(DDR)inhibitors have garnered significant attention due to their potent therapeutic potential across various malignancies.This review provides a detailed analysis of DDR pathways as therapeutic targets in GBM,summarizes recent advancements,therapeutic strategies,and ongoing clinical trials,and offers perspectives on future directions in this rapidly evolving field.The goal is to present a comprehensive outlook on the potential of DDR inhibitors in improving GBM management and outcomes.

Lipid metabolic reprogramming as an emerging mechanism of resistance to kinase inhibitors in breast cancer

Breast cancer is one of the leading causes of death in women in the United States.In general,patients with breast cancer undergo surgical resection of the tumor and/or receive drug treatment to kill or suppress the growth of cancer cells.In this regard,small molecule kinase inhibitors serve as an important class of drugs used in clinical and research settings.However,the development of resistance to these compounds,in particular HER2 and CDK4/6 inhibitors,often limits durable clinical responses to therapy.Emerging evidence indicates that PI3K/AKT/mTOR pathway hyperactivation is one of the most prominent mechanisms of resistance to many small molecule inhibitors as it bypasses upstream growth factor receptor inhibition.Importantly,the PI3K/AKT/mTOR pathway also plays a pertinent role in regulating various aspects of cancer metabolism.Recent studies from our lab and others have demonstrated that altered lipid metabolism mediates the development of acquired drug resistance to HER2-targeted therapies in breast cancer,raising an interesting link between reprogrammed kinase signaling and lipid metabolism.It appears that,upon development of resistance to HER2 inhibitors,breast cancer cells rewire lipid metabolism to somehow circumvent the inhibition of kinase signaling.Here,we review various mechanisms of resistance observed for kinase inhibitors and discuss lipid metabolism as a potential therapeutic target to overcome acquired drug resistance.

Towards understandings of serine/arginine-rich splicing factors

Serine/arginine-rich splicing factors(SRSFs)refer to twelve RNA-binding proteins which regulate splice site recognition and spliceosome assembly during precursor messenger RNA splicing.SRSFs also participate in other RNA metabolic events,such as transcription,translation and nonsensemediated decay,during their shuttling between nucleus and cytoplasm,making them indispensable for genome diversity and cellular activity.Of note,aberrant SRSF expression and/or mutations elicit fallacies in gene splicing,leading to the generation of pathogenic gene and protein isoforms,which highlights the therapeutic potential of targeting SRSF to treat diseases.In this review,we updated current understanding of SRSF structures and functions in RNA metabolism.Next,we analyzed SRSF-induced aberrant gene expression and their pathogenic outcomes in cancers and non-tumor diseases.The development of some well-characterized SRSF inhibitors was discussed in detail.We hope this review will contribute to future studies of SRSF functions and drug development targeting SRSFs.

Preclinical and early clinical studies of a novel compound SYHA1813 that efficiently crosses the blood-brain barrier and exhibits potent activity against glioblastoma

Glioblastoma(GBM)is the most common and aggressive malignant brain tumor in adults and is poorly controlled.Previous studies have shown that both macrophages and angiogenesis play significant roles in GBM progression,and co-targeting of CSF1R and VEGFR is likely to be an effective strategy for GBM treatment.Therefore,this study developed a novel and selective inhibitor of CSFIR and VEGFR,SYHA1813,possessing potent antitumor activity against GBM.SYHA1813 inhibited VEGFR and CSFIR kinase activities with high potency and selectivity and thus blocked the cell viability of HUVECs and macrophages and exhibited anti-angiogenetic effects both in vitro and in vivo.SYHA1813 also displayed potent in vivo antitumor activity against GBM in immune-competent and immune-deficient mouse models,including temozolomide(TMZ)insensitive tumors.Notably,SYHA1813 could penetrate the blood-brain barrier(BBB)and prolong the survival time of mice bearing intracranial GBM xenografts.Moreover,SYHA1813 treatment resulted in a synergistic antitumor efficacy in combination with the PD-1 antibody.As a clinical proof of concept,SYHA1813 achieved confirmed responses in patients with recurrent GBM in an ongoing first-in-human phase I trial.The data of this study support the rationale for an ongoing phase I clinical study(ChiCTR2100045380).

Function,mechanism and drug discovery of ubiquitin and ubiquitin-like modification with multiomics profiling for cancer therapy

Ubiquitin(Ub)and ubiquitin-like(Ubl)pathways are critical post-translational modifications that determine whether functional proteins are degraded or activated/inactivated.To date,>600 associated enzymes have been reported that comprise a hierarchical task network(e.g.,E1–E2–E3 cascade enzymatic reaction and deubiquitination)to modulate substrates,including enormous oncoproteins and tumor-suppressive proteins.Several strategies,such as classical biochemical approaches,multiomics,and clinical sample analysis,were combined to elucidate the functional relations between these enzymes and tumors.In this regard,the fundamental advances and follow-on drug discoveries have been crucial in providing vital information concerning contemporary translational efforts to tailor individualized treatment by targeting Ub and Ubl pathways.Correspondingly,emphasizing the current progress of Ub-related pathways as therapeutic targets in cancer is deemed essential.In the present review,we summarize and discuss the functions,clinical significance,and regulatory mechanisms of Ub and Ubl pathways in tumorigenesis as well as the current progress of small-molecular drug discovery.In particular,multiomics analyses were integrated to delineate the complexity of Ub and Ubl modifications for cancer therapy.The present review will provide a focused and up-to-date overview for the researchers to pursue further studies regarding the Ub and Ubl pathways targeted anticancer strategies.

Anticancer drug discovery by targeting cullin neddylation

Protein neddylation is a post-translational modification which transfers the ubiquitin-like protein NEDD8 to a lysine residue of the target substrate through a three-step enzymatic cascade.The bestknown substrates of neddylation are cullin family proteins,which are the core component of Cullin-RING E3 ubiquitin ligases(CRLs).Given that cullin neddylation is required for CRL activity,and CRLs control the turn-over of a variety of key signal proteins and are often abnormally activated in cancers,targeting neddylation becomes a promising approach for discovery of novel anti-cancer therapeutics.In the past decade,we have witnessed significant progress in the field of protein neddylation from preclinical target validation,to drug screening,then to the clinical trials of neddylation inhibitors.In this review,we first briefly introduced the nature of protein neddylation and the regulation of neddylation cascade,followed by a summary of all reported chemical inhibitors of neddylation enzymes.We then discussed the structure-based targeting of protein-protein interaction in neddylation cascade,and finally the available approaches for the discovery of new neddylation inhibitors.This review will provide a focused,up-to-date and yet comprehensive overview on the discovery effort of neddylation inhibitors.