Histone methyl transferases: A class of epigenetic opportunities to counter uncontrolled cell proliferation

The role and molecular mechanism of Trametes Robiniophila Murr(Huaier) in tumor therapy

ETHNOPHARMACOLOGICAL RELEVANCE

Trametes Robiniophila Murr, commonly known as Huaier, has been extensively documented in ethnopharmacology research in China. Huaier has a long history of clinical usage spanning over 1000 years in China. Traditional clinical application records demonstrate the wide utilization of Huaier for treating various cancers and enhancing the autoimmunity of tumor patients.

AIM OF THE REVIEW

The present study provides a comprehensive review of the traditional uses, phytochemical constituents, pharmacological activities, anti-tumor mechanism, and potential applications of Huaier, thereby offering valuable insights for the further development and utilization of this natural product.

MATERIALS AND METHODS

This study employed the keywords "Trametes Robiniophila Murr" and "Huaier" to retrieve relevant information on Huaier from various databases, including PubMed, Web of Science, Springer, Science Direct, ACS, Wiley, CNKI, Baidu Scholar, Google Scholar, and ancient materia medica.

RESULTS

Trametes Robiniophila Murr (Huaier), a traditional Chinese medicine, has demonstrated significant efficacy in the clinical treatment of various tumors. The primary bioactive constituents of Huaier consist of fungal-derived compounds, including polysaccharides, proteins, ketones, alkaloids, and minerals. The research findings demonstrate that Huaier serves as a reliable adjunctive therapeutic agent by effectively inhibiting cancer cell proliferation, inducing apoptosis in cancer cells, suppressing tumor metastasis, regulating tumor stem cells and immune function. Therefore, it exerts a potent anti-tumor effect when used in conjunction with conventional anti-cancer therapies.

CONCLUSIONS

The analysis of traditional uses, phytochemical composition, and pharmacological activity reveals that Huaier exhibits significant potential as a medicinal plant with diverse pharmacological effects. Owing to its numerous advantages, Huaier holds immense promise for application in the domains of tumor prevention and treatment, enhancing both survival time and quality of life among cancer patients.

Anticancer Potential of the S-Heterocyclic Ring Containing Drugs and its Bioactivation to Reactive Metabolites

Sulfur-containing heterocyclic derivatives have been disclosed for binding with a wide range of cancer-specific protein targets. Various interesting derivatives of sulfur-containing heterocyclics such as benzothiazole, thiazole, thiophene, thiazolidinedione, benzothiophene, and phenothiazine, etc have been shown to inhibit diverse signaling pathways implicated in cancer. Significant progress has also been made in molecular targeted therapy against specific enzymes such as kinase receptors due to potential binding interactions inside the ATP pocket. Sulfur-containing heterocyclic ring metal complexes i. e., benzothiazole, thiazole, thiophene, benzothiophene and phenothiazines are among the most promising active anticancer compounds. However, sulfur heteroaromatic rings, particularly thiophene, are of high structural alert due to their metabolism to reactive metabolites. The mere presence of a structural alert itself does not determine compound toxicity therefore, this review focuses on some specific findings that shed light on factors influencing the toxicity. In the current review, synthetic strategies of introducing the sulfur core ring in the synthesized derivatives are discussed with their structure-activity relationships to enhance our understanding of toxicity mechanisms and develop safer therapeutic options. The sulfur-containing marketed anticancer drugs included in this review direct the synthesis of novel compounds and will help in the development of potent, safer sulfur-based anticancer drugs in near future.

The role of miR-155 on liver diseases by modulating immunity, inflammation and tumorigenesis

The liver is a well-known metabolic organ that can be susceptible to external stimuli to affect its normal physiological function. Worldwide, the morbidity and mortality of liver diseases are skyrocketing every year, causing human health crises. Recently, new approaches such as biotechnology have been introduced to achieve optimal treatment and prognostic management of liver diseases. microRNAs (miRNAs), a kind of small non-coding RNA molecule, have the advantages of biodiversity, wide distribution and numerous members. Among these miRNAs, miR-155 is an important regulator of inflammation, immunity and tumorigenesis. In this review, the PubMed and Web of Science databases were searched from 2009 to 2022. After inclusion and exclusion, 64 articles were selected for a systematic review to comprehensively summarize the mechanisms of miR-155 regulating inflammation, immunity and tumorigenesis in liver diseases and liver cancer, covering in vitro, in vivo and clinical studies. Existing preclinical studies and clinical trials have listed that the up-regulation and down-regulation of miR-155 are significant in alcoholic liver injury, viral hepatitis, autoimmune hepatitis, infectious liver injury, liver transplantation and liver cancer. The immune and inflammation effects of miR-155 are manifested by regulating macrophage polarization, NK cell killing, Th17 cell and Th1/Th2 cell differentiation. Additionally, miR-155 is also committed to participating in the cell cycle, invasion and metastasis, immune escape and other processes to promote and intensify the development of liver cancer. In conclusion, miR-155 is not only a biomarker for the diagnosis and prognosis of liver diseases, but also plays a therapeutic role via regulating immunity, inflammation and tumorigenesis.

Targeting Epigenetic Changes Mediated by Members of the SMYD Family of Lysine Methyltransferases

A comprehensive understanding of the mechanisms involved in epigenetic changes in gene expression is essential to the clinical management of diseases linked to the SMYD family of lysine methyltransferases. The five known SMYD enzymes catalyze the transfer of donor methyl groups from S-adenosylmethionine (SAM) to specific lysines on histones and non-histone substrates. SMYDs family members have distinct tissue distributions and tissue-specific functions, including regulation of development, cell differentiation, and embryogenesis. Diseases associated with SMYDs include the repressed transcription of SMYD1 genes needed for the formation of ion channels in the heart leading to heart failure, SMYD2 overexpression in esophageal squamous cell carcinoma (ESCC) or p53-related cancers, and poor prognosis associated with SMYD3 overexpression in more than 14 types of cancer including breast cancer, colon cancer, prostate cancer, lung cancer, and pancreatic cancer. Given the importance of epigenetics in various pathologies, the development of epigenetic inhibitors has attracted considerable attention from the pharmaceutical industry. The pharmacologic development of the inhibitors involves the identification of molecules regulating both functional SMYD SET (Suppressor of variegation, Enhancer of Zeste, Trithorax) and MYND (Myeloid-Nervy-DEAF1) domains, a process facilitated by available X-ray structures for SMYD1, SMYD2, and SMYD3. Important leads for potential pharmaceutical agents have been reported for SMYD2 and SMYD3 enzymes, and six epigenetic inhibitors have been developed for drugs used to treat myelodysplastic syndrome (Vidaza, Dacogen), cutaneous T-cell lymphoma (Zoinza, Isrodax), and peripheral T-cell lymphoma (Beleodag, Epidaza). The recently demonstrated reversal of SMYD histone methylation suggests that reversing the epigenetic effects of SMYDs in cancerous tissues may be a desirable target for pharmacological development.

Targeting epigenetic regulators to overcome drug resistance in cancers

Drug resistance is mainly responsible for cancer recurrence and poor prognosis. Epigenetic regulation is a heritable change in gene expressions independent of nucleotide sequence changes. As the common epigenetic regulation mechanisms, DNA methylation, histone modification, and non-coding RNA regulation have been well studied. Increasing evidence has shown that aberrant epigenetic regulations contribute to tumor resistance. Therefore, targeting epigenetic regulators represents an effective strategy to reverse drug resistance. In this review, we mainly summarize the roles of epigenetic regulation in tumor resistance. In addition, as the essential factors for epigenetic modifications, histone demethylases mediate the histone or genomic DNA modifications. Herein, we comprehensively describe the functions of the histone demethylase family including the lysine-specific demethylase family, the Jumonji C-domain-containing demethylase family, and the histone arginine demethylase family, and fully discuss their regulatory mechanisms related to cancer drug resistance. In addition, therapeutic strategies, including small-molecule inhibitors and small interfering RNA targeting histone demethylases to overcome drug resistance, are also described.

Ranunculus ternatus Thunb extract attenuates renal fibrosis of diabetic nephropathy via inhibiting SMYD2

CONTEXT

Ranunculus ternatus Thunb (Ranunculaceae), (RTT) is used clinically for the treatment of tuberculosis or as tumour adjuvant therapy, but its potential effect on diabetic nephropathy (DN) has not been studied.

OBJECTIVE

To investigate the effect of RTT extract in renal fibrosis of DN.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into four groups (n = 12). Diabetes mellitus (DM) mice were induced by streptozotocin (STZ, 55 mg/kg/day) for five consecutive days and treated by RTT extract (2 g/kg). Afterward, blood glucose, HE and Masson staining were assayed. The expression levels of Vimentin, ɑ-SMA, TNF-ɑ, NF-κB p-p65, NF-κB p65, SMYD2, H3K36me3, H3K4me3 were determined by western blots. Firbronectin was respectively assayed by western blot and immunofluorescent staining.

RESULTS

RTT extract significantly ameliorated renal injury and renal fibrosis in the renal tissue of STZ-induced diabetic mice as demonstrated by the decreased expression level of Fibronectin (65%), Vimentin and α-SMA (75% & 53%). In addition, the levels of TNF-α (57%), NF-κB p-p65 and NF-κB p65 (35% & 25%) were elevated in the DN mice. Importantly, these were alleviated after RTT extract treatment. Moreover, we observed that the protein levels of SMYD2 (30%), H3K36me3 and H3K4me3 (53% & 75%) were reduced in DN mice after treatment with RTT extract.

DISCUSSION AND CONCLUSIONS

RTT extract mediates antifibrotic effects and anti-inflammatory responses in STZ-induced DN mainly through suppressing SMYD2 activation and H3K36me3 and H3K4me3 protein expression. RTT extract might have therapeutic potential against high glucose-induced nephropathy.

Comprehensive analysis of histone methylation modification regulators for predicting prognosis and drug sensitivity in lung adenocarcinoma

Histone methylation is an epigenetic modification regulated by histone methyltransferases, histone demethylases, and histone methylation reader proteins that play important roles in the pathogenic mechanism of cancers. However, the prognostic value of histone methylation in lung adenocarcinoma (LUAD) remains unknown. Here, we found that LUAD cases could be divided into 2 subtypes by the 144 histone methylation modification regulators (HMMRs), with a significant difference in OS time. Ninety-five of the HMMRs were identified as differentially expressed genes (DEGs) between normal and tumor samples, and 13 of them were further discovered to be survival-related genes (SRGs). By applying the least absolute shrinkage and selector operator (LASSO) Cox regression, we constructed an 8-gene-based risk signature according to the TCGA (training) cohort, and the risk score calculated by the signature was proven to be an independent factor in both the training and validation cohorts. We then discovered that the immune functions were generally impaired in the high-risk groups defined by the HMMR signature (especially for the DCs and immune check-point pathway). Functional analyses showed that the DEGs between the low- and high-risk groups were related to the cell cycle. The drug sensitivity analysis indicated that our risk model could predict the sensitivity of commonly used drugs. Moreover, according to the DEGs between the low- and high-risk groups, we discovered several new compounds that showed potential therapeutic value for high-risk LUAD patients. In conclusion, our study demonstrated that HMMRs were promising predictors for the prognoses and drug therapeutic effects for LUAD patients.

SMYD3 promotes aerobic glycolysis in diffuse large B-cell lymphoma via H3K4me3-mediated PKM2 transcription

Genetic abnormalities in histone methyltransferases (HMTs) frequently occur in diffuse large B-cell lymphoma (DLBCL) and are related to its progression. SET and MYND domain containing 3 (SMYD3) is an HMT that is upregulated in various tumors and promotes their malignancy. However, to the best of our knowledge, the function of SMYD3 in DLBCL has not been investigated thus far. In the present study, 22 HMT genes related to cancer development were first selected according to current literature, and it was found that high SMYD3 expression was significantly associated with poor progression-free survival in patients with DLBCL. SMYD3 protein levels were upregulated and positively associated with poor prognosis and poor responsiveness to chemotherapy in patients with DLBCL. Functional examinations demonstrated that SMYD3 increased cell proliferation and the flux of aerobic glycolysis in DLBCL cells in vitro and in vivo and decreased cell sensitivity to doxorubicin in vitro. Moreover, SMYD3 could directly bind to specific sequences of Pyruvate Kinase M2 (PKM2) and promote DLBCL cell proliferation and aerobic glycolysis via H3K4me3-mediated PKM2 transcription. Clinically, SMYD3 expression positively correlated with that of PKM2, and high SMYD3 was significantly associated with high maximum standardized uptake value (SUVmax) detected by [(18)F]-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (PET/CT) in DLBCL samples. Concomitant expression of SMYD3 and PKM2 positively correlated with poor progression-free and overall survival in patients with DLBCL and may serve as novel biomarkers in DLBCL.

Targeting Histone Epigenetic Modifications and DNA Damage Responses in Synthetic Lethality Strategies in Cancer?

Synthetic lethality strategies are likely to be integrated in effective and specific cancer treatments. These strategies combine different specific targets, either in similar or cooperating pathways. Chromatin remodeling underlies, directly or indirectly, all processes of tumor biology. In this context, the combined targeting of proteins associated with different aspects of chromatin remodeling can be exploited to find new alternative targets or to improve treatment for specific individual tumors or patients. There are two major types of proteins, epigenetic modifiers of histones and nuclear or chromatin kinases, all of which are druggable targets. Among epigenetic enzymes, there are four major families: histones acetylases, deacetylases, methylases and demethylases. All these enzymes are druggable. Among chromatin kinases are those associated with DNA damage responses, such as Aurora A/B, Haspin, ATM, ATR, DNA-PK and VRK1-a nucleosomal histone kinase. All these proteins converge on the dynamic regulation chromatin organization, and its functions condition the tumor cell viability. Therefore, the combined targeting of these epigenetic enzymes, in synthetic lethality strategies, can sensitize tumor cells to toxic DNA-damage-based treatments, reducing their toxicity and the selective pressure for tumor resistance and increasing their immunogenicity, which will lead to an improvement in disease-free survival and quality of life.

Understanding Household Catastrophic Health Expenditures and Fairness of Financing for Cancer Treatment: A Cross-Sectional Case Study in West of Iran

Background: Direct out-of-pocket (OOP) and indirect healthcare payments can limit the household budget and cause several financial problems for the household. Objectives: This study aimed to measure the financial protection and determinants of catastrophic health expenditures (CHEs) for cancer treatment in Shahid Rahimi Hospital, Khorramabad, located in western Iran. Methods: This study was conducted on 220 households of cancer patients in Lorestan Province, Iran. The framework of data collection was based on the World Health Organization (WHO) Global Health Survey. Interviews were conducted with individuals who met the inclusion criteria of this study; they were selected using a simple random sampling method. Data were analyzed using Chi-square test in STATA. Results: The present results showed that the incidence of CHEs and the fair financial contribution index (FFCI) were 70% and 86%, respectively. There was a significant relationship between the household CHEs and variables, such as supplementary insurance coverage, household income status, educational level of the household head, household size, age of the household head, type of cancer, and type of cancer treatment. Conclusions: More financial protection should be provided for the families of cancer patients due to the high incidence of CHEs and unfair financing of cancer care services. Moreover, healthcare systems should consider supportive policies for cancer patients and their household members by increasing the insurance coverage and expanding service packages to reduce cancer treatment expenditures.

Screening for Small-Molecule Inhibitors of Histone Methyltransferases

Potent and highly selective small-molecule inhibitors are needed to unravel the biological complexities of histone methyltransferases and to reveal their therapeutic potential. A prerequisite to developing these inhibitors is the identification of validated chemical matter for initiating a medicinal chemistry campaign. For the most part, finding these initial starting points occurs through screening of large, unbiased compound libraries. The size and nature of these libraries, coupled with the complexities of the bisubstrate utilizing histone methyltransferases, necessitates that the primary screen and subsequent hit triage be carefully considered.In this chapter, using EZH2 as a representative example, we describe a screening and hit triage campaign that identified validated chemical matter allowing initiation of medicinal chemistry studies. Moreover, we discuss a cell-based assay to support lead identification and optimization. The approach described here entailing a mixture of biochemical, biophysical and cell-based assays should be applicable to identifying validated starting points for other histone methyltransferases.

BIX01294 inhibits EGFR signaling in EGFR-mutant lung adenocarcinoma cells through a BCKDHA-mediated reduction in the EGFR level

BIX01294 (BIX), an inhibitor of the G9a histone methyltransferase, has been reported to have antitumor activity against a variety of cancers. However, the molecular mechanisms underlying its anticancer effects, particularly those against lung cancer, remain unclear. Here, we report that BIX induces apoptotic cell death in EGFR-mutant non-small cell lung cancer (NSCLC) cells but not in their wild-type counterparts. Treatment with BIX resulted in a significant reduction in the EGFR level and inhibition of EGFR signaling only in EGFR-mutant NSCLC cells, leading to apoptosis. BIX also inhibited mitochondrial metabolic function and decreased the cellular energy levels that are critical for maintaining the EGFR level. Furthermore, BIX transcriptionally downregulated the transcription of branched-chain α-keto acid dehydrogenase (BCKDHA), which is essential for fueling the tricarboxylic acid (TCA) cycle. Interestingly, this BCKDHA downregulation was due to inhibition of Jumanji-domain histone demethylases but not the G9a histone methyltransferase. We observed that KDM3A, a Jumonji histone demethylase, epigenetically regulates BCKDHA expression by binding to the BCKDHA gene promoter. BIX exposure also led to a significant decrease in the EGFR level, causing apoptosis in EGFR-TKI (tyrosine kinase inhibitor)-resistant cell lines, which are dependent on EGFR signaling for survival. Taken together, our current data suggest that BIX triggers apoptosis only in EGFR-mutant NSCLC cells via inhibition of BCKDHA-mediated mitochondrial metabolic function.

A drug known as BIX that is effective against bladder and breast cancers may also be effective in fighting non-small cell lung cancer (NSCLC). Although advances have been made in treatment of NSCLC, one of the most effective drugs targets a protein called EGFR, and EGFR gene mutations that lead to acquired drug resistance are common. Jaekyoung Son at the University of Ulsan, Seoul, South Korea, and colleagues investigated whether BIX is effective against NSCLC and attempted to elucidate its mechanism of action. The researchers found that BIX caused death of NSCLC cells, especially those with mutations in the EGFR gene. Further investigation showed that BIX was effective even against drug-resistant NSCLC cells, by acting via a different metabolic pathway. BIX shows promise as an alternative therapy for lung cancer, to overcome drug resistance.

A novel SIRT6 activator ameliorates neuroinflammation and ischemic brain injury via EZH2/FOXC1 axis

Ischemic stroke is the second leading cause of death worldwide with limited medications and neuroinflammation was recognized as a critical player in the progression of stroke, but how to control the overactive neuroinflammation is still a long-standing challenge. Here, we designed a novel SIRT6 activator MDL-811 which remarkably inhibited inflammatory response in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and primary mouse microglia, which were abolished by silencing SIRT6. RNA-seq screening identified the forkhead box C1 (Foxc1) is a key gene evoked by MDL-811 stimulation and is required for the anti-inflammatory effects of MDL-811. We found MDL-811-activated SIRT6 directly interacted with enhancer of zeste homolog 2 (EZH2) and promoted deacetylation of EZH2 which could bind to the promoter of Foxc1 and upregulate its expression to modulate inflammation. Moreover, our data demonstrated that MDL-811 not only ameliorated sickness behaviors in neuroinflammatory mice induced by LPS, but also markedly reduced the brain injury in ischemic stroke mice in addition to promoting long-term functional recovery. Importantly, MDL-811 also exhibited strong anti-inflammatory effects in human monocytes isolated from ischemic stroke patients, underlying an interesting translational perspective. Taken together, MDL-811 could be an alternative therapeutic candidate for ischemic stroke and other brain disorders associated with neuroinflammation.

Synthesis, inverse docking-assisted identification and in vitro biological characterization of Flavonol-based analogs of fisetin as c-Kit, CDK2 and mTOR inhibitors against melanoma and non-melanoma skin cancers

Due to hurdles, including resistance, adverse effects, and poor bioavailability, among others linked with existing therapies, there is an urgent unmet need to devise new, safe, and more effective treatment modalities for skin cancers. Herein, a series of flavonol-based derivatives of fisetin, a plant-based flavonoid identified as an anti-tumorigenic agent targeting the mammalian targets of rapamycin (mTOR)-regulated pathways, were synthesized and fully characterized. New potential inhibitors of receptor tyrosine kinases (c-KITs), cyclin-dependent kinase-2 (CDK2), and mTOR, representing attractive therapeutic targets for melanoma and non-melanoma skin cancers (NMSCs) treatment, were identified using inverse-docking, in vitro kinase activity and various cell-based anticancer screening assays. Eleven compounds exhibited significant inhibitory activities greater than the parent molecule against four human skin cancer cell lines, including melanoma (A375 and SK-Mel-28) and NMSCs (A431 and UWBCC1), with IC50 values ranging from 0.12 to < 15 μM. Seven compounds were identified as potentially potent single, dual or multi-kinase c-KITs, CDK2, and mTOR kinase inhibitors after inverse-docking and screening against twelve known cancer targets, followed by kinase activity profiling. Moreover, the potent compound F20, and the multi-kinase F9 and F17 targeted compounds, markedly decreased scratch wound closure, colony formation, and heightened expression levels of key cancer-promoting pathway molecular targets c-Kit, CDK2, and mTOR. In addition, these compounds downregulated Bcl-2 levels and upregulated Bax and cleaved caspase-3/7/8 and PARP levels, thus inducing apoptosis of A375 and A431 cells in a dose-dependent manner. Overall, compounds F20, F9 and F17, were identified as promising c-Kit, CDK2 and mTOR inhibitors, worthy of further investigation as therapeutics, or as adjuvants to standard therapies for the control of melanoma and NMSCs.

Histone methyltransferase and drug resistance in cancers

A number of novel anticancer drugs have been developed in recent years. However, the mortality of cancer patients remains high because of the emergence of drug resistance. It was reported that drug resistance might involved in changes in gene expression without changing genotypes, which is similar to epigenetic modification. Some studies indicated that targeting histone methyltransferase can reverse drug resistance. Hence, the use of histone methyltransferase inhibitors or histone demethylase inhibitors opens new therapeutic approaches for cancer treatment. While the relationship between histone methyltransferase and tumor resistance has been determined, there is a lack of updated review on the association between them. In this review, we summarized the mechanisms of histone methyltransferases in cancer drug resistance and the therapeutic strategies of targeting histone methyltransferase to reverse drug resistance.

The histone methyltransferase SMYD2 is a novel therapeutic target for the induction of apoptosis in ovarian clear cell carcinoma cells

Previous studies have suggested that histone methylation can modulate carcinogenesis and cancer progression. For instance, the histone methyltransferase SET and MYND domain containing 2 (SMYD2) is overexpressed in several types of cancer tissue. The aim of the present study was to determine whether SMYD2 could serve a therapeutic role in ovarian clear cell carcinoma (OCCC). Reverse transcription-quantitative PCR was used to examine SMYD2 expression in 23 clinical OCCC specimens. Moreover, OCCC cell proliferation and cell cycle progression were also examined following small interfering RNA-mediated SMYD2 silencing or treatment with a selective SMYD2 inhibitor. SMYD2 was significantly upregulated in clinical OCCC specimens, compared with normal ovarian tissue. In addition, SMYD2 knockdown decreased cell viability as determined via a Cell Counting Kit-8 assay. Moreover, the proportion of cells in the sub-G₁ phase increased following SMYD2 knockdown, suggesting increased apoptosis. Treatment with the SMYD2 inhibitor LLY-507 suppressed OCCC cell viability. These results suggested that SMYD2 could promote OCCC viability, and that SMYD2 inhibition induced apoptosis in these cells. Thus, SMYD2 inhibitors may represent a promising molecular targeted approach for OCCC treatment.

Thiophene-based derivatives as anticancer agents: An overview on decade's work

Heterocyclic compounds hold a pivotal place in medicinal chemistry due to their wide range of biological activities and thus, are exhaustively explored in the field of drug design and development. Continuous efforts are being carried out for the development of medicinal agents especially, for dreadful diseases like cancer. Thiophene, a sulfur containing heterocyclic scaffold, has emerged as one of the relatively well-explored scaffold for the development of library of molecules having potential anticancer profile. Thiophene analogs have been reported to bind with a wide range of cancer-specific protein targets, depending on the nature and position of substitutions. Accordingly, thiophene analogs have been reported to cause their biological action through inhibition of different signaling pathways involved in cancer. Functionally, different anticancer targets require different structural features, so researchers have tried to synthesize new thiophene derivatives with varied substitutions. In the present review, authors have presented the information available on thiophene-based molecules as anticancer agents with special focus on synthetic methodologies, biological profile and structure activity relationship (SAR) studies. Various patents granted for thiophene containing molecules as anticancer have also been included.

Trametes robiniophila Murr in the treatment of breast cancer

Breast cancer is the leading cause of cancer death among women across the world. Trametes robiniophila Murr (Huaier), a traditional herbal medicine, has been used in China to protect human health for about 1600 years. Recent years, Huaier had been proven to be effective for multiple types of malignancies. This systematic review focused on breast cancer treatment, summarizing the curative function of Huaier aqueous extract and polysaccharides in preclinical researches. Huaier could markedly inhibit breast cancer progression with low toxicity, enhance immune response and increase the sensitivity to radiation and chemotherapy. The therapeutic effect of Huaier granule in clinical studies was also included. This review amalgamated the current studies and highlighted the promising role of Huaier and its polysaccharides as complementary alternative medicine in breast cancer treatment.

An update on chemical classes targeting ERK1/2 for the management of cancer

Cancer, still in the limelight due to its dreadful nature, shows overexpression of multiple signaling macromolecules leading to failure of many chemotherapeutic agents and acquired resistance to chemotherapy. These factors highlight the significance of shifting toward targeted therapy in cancer research. Recently, ERKs (ERK1 and 2) have been established as a promising target for the management of various types of solid tumors, due to their aberrant involvement in cell growth and progression. Several ERKs inhibitors have reached clinical trials for the management of cancer and their derivatives are being continuously reported with noteworthy anticancer effect. This review highlights the recent reports on various chemical classes involved in the development of ERKs inhibitors along with their in vitro and in vivo activity and structure-activity relationship profile.

Identification of DOT1L inhibitors by structure-based virtual screening adapted from a nucleoside-focused library

Disruptor of Telomeric Silencing 1-Like (DOT1L), the sole histone H3 lysine 79 (H3K79) methyltransferase, is required for leukemogenic transformation in a subset of leukemias bearing chromosomal translocations of the Mixed Lineage Leukemia (MLL) gene, as well as other cancers. Thus, DOT1L is an attractive therapeutic target and discovery of small molecule inhibitors remain of high interest. Herein, we are presenting screening results for a unique focused library of 1200 nucleoside analogs originally produced under the aegis of the NIH Pilot Scale Library Program. The complete nucleoside set was screened virtually against DOT1L, resulting in 210 putative hits. In vitro screening of the virtual hits resulted in validation of 11 compounds as DOT1L inhibitors clustered into two distinct chemical classes, adenosine-based inhibitors and a new chemotype that lacks adenosine. Based on the developed DOT1L ligand binding model, a structure-based design strategy was applied and a second-generation of non-nucleoside DOT1L inhibitors was developed. Newly synthesized compound 25 was the most potent DOT1L inhibitor in the new series with an IC₅₀ of 1.0 μM, showing 40-fold improvement in comparison with hit 9 and exhibiting reasonable on target effects in a DOT1L dependent murine cell line. These compounds represent novel chemical probes with a unique non-nucleoside scaffold that bind and compete with the SAM binding site of DOT1L, thus providing foundation for further medicinal chemistry efforts to develop more potent compounds.

Discovery of 3-(((9H-purin-6-yl)amino)methyl)-4,6-dimethylpyridin-2(1H)-one derivatives as novel tubulin polymerization inhibitors for treatment of cancer

A new series of 3-(((9H-purin-6-yl)amino)methyl)-4,6-dimethylpyridin-2(1H)-one derivatives were designed, synthesized and demonstrated to act as tubulin polymerization inhibitors. These new derivatives showed significant antitumor activities, among which SKLB0533 demonstrated to be the most potent compound, with IC₅₀ values ranging from 44.5 to 135.5 nM against seven colorectal carcinoma (CRC) cell lines. Remarkably, SKLB0533 exhibited no activity against other potential targets, such as 420 kinases and EZH2. Besides, SKLB0533 inhibited tubulin polymerization, arrested the cell cycle at the G2/M phase and induced apoptosis in CRC cells. Furthermore, SKLB0533 suppressed tumour growth in the HCT116 xenograft model without inducing notable major organ-related toxicity, suggesting that SKLB0533 could be used as a promising lead compound for the development of new antitumor agents.