Novel sulfonamide-indolinone hybrids targeting mitochondrial respiration of breast cancer cells.

Breast cancer (BC) still poses a threat worldwide which demands continuous efforts to present safer and efficacious treatment options via targeted therapy. Beside kinases' aberrations as Aurora B kinase which controls cell division, BC adopts distinct metabolic profiles to meet its high energy demands. Accordingly, targeting both aurora B kinase and/or metabolic vulnerability presents a promising approach to tackle BC. Based on a previously reported indolinone-based Aurora B kinase inhibitor (III), and guided by structural modification and SAR investigation, we initially synthesized 11 sulfonamide-indolinone hybrids (5a-k), which showed differential antiproliferative activities against the NCI-60 cell line panel with BC cells displaying preferential sensitivity. Nonetheless, modest activity against Aurora B kinase (18-49% inhibition) was noted at 100 nM. Screening of a representative derivative (5d) against 17 kinases, which are overexpressed in BC, failed to show significant activity at 1 µM concentration, suggesting that kinase inhibitory activity only played a partial role in targeting BC. Bioinformatic analyses of genome-wide transcriptomics (RNA-sequencing), metabolomics, and CRISPR loss-of-function screens datasets suggested that indolinone-completely responsive BC cell lines (MCF7, MDA-MB-468, and T-47D) were more dependent on mitochondrial oxidative phosphorylation (OXPHOS) compared to partially responsive BC cell lines (MDA-MB-231, BT-549, and HS 578 T). An optimized derivative, TC11, obtained by molecular hybridization of 5d with sunitinib polar tail, manifested superior antiproliferative activity and was used for further investigations. Indeed, TC11 significantly reduced/impaired the mitochondrial respiration, as well as mitochondria-dependent ROS production of MCF7 cells. Furthermore, TC11 induced G0/G1 cell cycle arrest and apoptosis of MCF7 BC cells. Notably, anticancer doses of TC11 did not elicit cytotoxic effects on normal cardiomyoblasts and hepatocytes. Altogether, these findings emphasize the therapeutic potential of targeting the metabolic vulnerability of OXPHOS-dependent BC cells using TC11 and its related sulfonamide-indolinone hybrids. Further investigation is warranted to identify their precise/exact molecular target.

FLT3 inhibitors and novel therapeutic strategies to reverse AML resistance: An updated comprehensive review.

FMS-like tyrosine kinase 3 (FLT3) mutations occur in almost 30% of acute myeloid leukemia (AML) patients. Despite the initial clinical efficacy of FLT3 inhibitors, many treated AML patients with mutated FLT3 eventually relapse. This review critically discusses the opportunities and challenges of FLT3-targeted therapies and sheds light on their drug interactions as well as potential biomarkers. Furthermore, we focus on the molecular mechanisms underlying the resistance of FLT3 internal tandem duplication (FLT3-ITD) AMLs to FLT3 inhibitors alongside novel therapeutic strategies to reverse resistance. Notably, dynamic heterogeneous patterns of clonal selection and evolution contribute to the resistance of FLT3-ITD AMLs to FLT3 inhibitors. Ongoing preclinical research and clinical trials are actively directed towards devising rational "personalized" or "patient-tailored" combinatorial therapeutic regimens to effectively treat patients with FLT3 mutated AML.

Advances in acute myeloid leukemia differentiation therapy: A critical review.

Acute myeloid leukemia (AML) is characterized by impaired differentiation and indefinite proliferation of abnormal myeloid progenitors. Although differentiating agents were deemed to revolutionize AML therapy, most treated non-APL AML patients are refractory or relapse. According to cancer stem cell model, leukemia-initiating cells are the root cause of relapse given their unidirectional potential to generate differentiated AML blasts. Nonetheless, accumulating evidences emphasize the de-differentiation plasticity and leukemogenic potential of mature AML blasts and the frailty of targeting leukemic stem cells per se. This review critically discusses the potential and challenges of (lessons learnt from) conventional and novel differentiating agents in AML therapy. Although differentiating agents might hold promise, they should be exploited within the context of a rationale combination regimen eradicating all maturation/differentiation states of AML cells. The results of the routinely used immunophenotypic markers and/or morphological analyses of differentiation should be carefully interpreted given their propensity to underestimate AML burden.

Discovery of EMD37, a 1,2,4-oxadiazole derivative, as a novel endoplasmic reticulum stress inducer with potent anticancer activity.

Targeting endoplasmic reticulum (ER) stress presents a promising strategy in cancer therapy. We previously reported a series of 1,2,4-oxadiazole derivatives that induced the degradation of EGFR and c-Met which are implicated in tumorigenesis. Based on our previous SAR studies, herein, we report the discovery of EMD37, a novel 1,2,4-oxadiazole derivative, which demonstrated potent anticancer activity against NCI-60 cancer cell lines panel compared to its parent/lead compounds. Anti-proliferative assays revealed preferential cytotoxicity of EMD37 on cancer cells compared to normal cells. Delving deeper, we exploited unbiased genome-wide transcriptome profiling of EMD37-treated cancer cells. Gene Ontology and gene set enrichment analyses revealed that EMD37 promoted ER stress and unfolded protein response (UPR) machinery which was confirmed using RT-qPCR. Mining drug signature databases also confirmed the enrichment of the signature of canonical UPR inducers. Knocking down ER stress transcription factors compromised at least partly the anticancer activity of EMD37. Immunoblot analysis showed that EMD37 induced the accumulation of polyubiquitinated proteins and inhibited mTOR signaling. EMD37 induced G2/M cell cycle arrest and apoptosis of human cancer cells. Inhibiting apoptosis evidently abrogated the anticancer efficacy of EMD37. Altogether, this study introduces EMD37 as a novel ER inducer which warrants further investigation as a potentially relevant anti-cancer therapy.

Preclinical activity of fluvastatin-loaded self-nanoemulsifying delivery system against breast cancer models: Emphasis on apoptosis.

Statins trigger apoptotic cell death in some types of growing tumor cells in a cholesterol-lowering-independent manner. Self-nanoemulsifying delivery systems (SNEDs) are potentially effective for the suppression of breast cancer development. This study aims to investigate the potential anticancer activity of fluvastatin (FLV)-SNEDs in breast cancer while comparing it with FLV in vitro as well as in vivo exploiting/using MDA-MB-231 and Erhlich ascites carcinoma (EAC)-bearing mice, respectively. Biochemical analysis of liver and kidney functions, oxidative stress markers, and histopathological examinations of such tumor tissues were performed showing the potentiality of SNEDs as a nanocarrier for antitumor agents. FLV-SNEDs demonstrated more potent anticancer activity compared to FLV on MDA-MB-231 and hepatocellular carcinoma (HepG2) cells. In vivo experiments on the EAC-bearing mice model indicated that FLV and-to a greater extent-FLV-SNEDs ameliorated EAC-induced hepatotoxicity and nephrotoxicity. FLV or FLV-SNEDs evidently reduced the percent of Ki-67 +ve EAC cells by 57.5% and 86.5% in comparison to the vehicle-treated EAC group. In addition, FLV or FLV-SNEDs decreased Bcl-2 levels in serum and liver specimens. In contrast, FLV or FLV-SNEDs significantly activated the executioner caspase-3. Simultaneously, both FLV and FLV-SNEDs stimulated p53 signaling and modulated Bcl-2 protein levels in treated cells. Collectively, these results support the contribution of apoptotic cell death in mediating the anticancer activities of FLV and FLV-SNEDs against murine EAC model in vivo. This study provides new understandings of how FLV and FLV-SNEDs regulate EAC cell viability via upregulation of p53 signaling, and through modulation of cleaved caspase-3 as well as antiapoptotic Bcl-2 marker.

Co-targeting leukemia-initiating cells and leukemia bulk leads to disease eradication.

According to a hierarchical model, targeting leukemia-initiating cells (LICs) was speculated to achieve complete remission (CR) or cure. Nonetheless, increasing evidence emphasized the plasticity of differentiated blasts undergoing interconversion into LICs. We exploited murine models of acute promyelocytic leukemia (APL), a subtype of acute myeloid leukemia driven by the promyelocytic leukemia/retinoic acid receptor (PML-RARα) oncofusion protein, which recruits histone deacetylase (HDAC)-containing complexes. We studied APLs with different LIC frequencies and investigated the effect of two HDAC inhibitors: valproic acid (VPA), with relative selectivity towards class I HDAC enzymes and vorinostat/suberoylanilide hydroxamic acid (SAHA) (pan-HDAC inhibitor) in combination with all-trans retinoic acid (ATRA), on the bulk APL cells and APL LICs. Indeed, we found that while VPA differentiates the bulk APL cells, SAHA selectively targets LICs. ATRA + VPA + SAHA combination efficiently induced CR in an APL model with lower LIC frequency. Substituting ATRA with synthetic retinoids as etretinate which promotes APL differentiation without downregulating PML/RARα compromised the therapeutic benefit of ATRA + VPA + SAHA regimen. Altogether, our study emphasizes the therapeutic power of co-targeting the plasticity and heterogeneity of cancer -herein demonstrated by tackling LICs and bulk leukemic blasts - to achieve and maintain CR.

Discovery of a benzimidazole-based dual FLT3/TrKA inhibitor targeting acute myeloid leukemia.

FMS-like tyrosine kinase 3 (FLT3) enzyme overexpression and mutations are the most common molecular abnormalities associated with acute myeloid leukemia (AML). In addition, recent studies investigated the role of tropomyosin receptor kinase A (TrKA) enzyme fusions in promoting AML growth and survival. Based on these premises, targeting both kinases using dual inhibitors would constitute a promising therapeutic approach to target resistant AML. Guided by ligand-based design and structure simplification of the FLT3 inhibitor, quizartinib, we developed a benzimidazole-based small molecule, 4ACP, that exhibited nanomolar activity against wild-type FLT3, FLT3-Internal tandem duplications (FLT3-ITD), and FLT3-D835Y (FLT3-TKD) mutation (IC50 = 43.8, 97.2, and 92.5 nM respectively). Additionally, 4ACP demonstrated potent activity against colon cancer KM12 cell line (IC50 = 358 nM) and subsequent mechanistic deconvolution identified TrKA enzyme as a second plausible target (IC50 = 23.6 nM) for our compound. 4ACP manifested preferential antiproliferative activity against FLT3-ITD positive AML cell lines (MV4-11 IC50 = 38.8 ± 10.7 nM and MOLM-13 IC50 = 54.9 ± 4.1 nM), while lacking activity against FLT3-ITD negative AML cell lines. Western blot analysis confirmed 4ACP ability to downregulate ERK1/2 and mTOR signaling downstream of FLT3-ITD in AML cells. Furthermore, 4ACP prompted apoptotic and necrotic cell death and G0/G1 cell cycle arrest as indicated by cell cycle analysis. 4ACP did not show cytotoxic effects on normal BNL and H9c2 cells and demonstrated decreased activity against c-Kit enzyme, hence, indicating lower probability of synthetic lethal toxicity and a relatively safer profile. In light of these data, 4ACP represents a novel FLT3/TrKA dual kinase inhibitor for targeted therapy of AML.

Indolin-2-one derivatives as selective Aurora B kinase inhibitors targeting breast cancer.

Aurora B is a pivotal cell cycle regulator where errors in its function results in polyploidy, genetic instability, and tumorigenesis. It is overexpressed in many cancers, consequently, targeting Aurora B with small molecule inhibitors constitutes a promising approach for anticancer therapy. Guided by structure-based design and molecular hybridization approach we developed a series of fifteen indolin-2-one derivatives based on a previously reported indolin-2-one-based multikinase inhibitor (1). Seven derivatives, 5g, 6a, 6c-e, 7, and 8a showed preferential antiproliferative activity in NCI-60 cell line screening and out of these, carbamate 6e and cyclopropylurea 8a derivatives showed optimum activity against Aurora B (IC50 = 16.2 and 10.5 nM respectively) and MDA-MB-468 cells (IC50 = 32.6 ± 9.9 and 29.1 ± 7.3 nM respectively). Furthermore, 6e and 8a impaired the clonogenic potential of MDA-MB-468 cells. Mechanistic investigations indicated that 6e and 8a induced G2/M cell cycle arrest, apoptosis, and necrosis of MDA-MB-468 cells and western blot analysis of 8a effect on MDA-MB-468 cells revealed 8a's ability to reduce Aurora B and its downstream target, Histone H3 phosphorylation. 6e and 8a displayed better safety profiles than multikinase inhibitors such as sunitinib, showing no cytotoxic effects on normal rat cardiomyoblasts and murine hepatocytes. Finally, 8a demonstrated a more selective profile than 1 when screened against ten related kinases. Based on these findings, 8a represents a promising candidate for further development to target breast cancer via Aurora B selective inhibition.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

Dendritic cell vaccine immunotherapy; the beginning of the end of cancer and COVID-19. A hypothesis.

Immunotherapy is the newest approach to combat cancer. It can be achieved using several strategies, among which is the dendritic cell (DC) vaccine therapy. Several clinical trials are ongoing using DC vaccine therapy either as a sole agent or in combination with other interventions to tackle different types of cancer. Immunotherapy can offer a potential treatment to coronavirus disease 2019 (COVID-19) the worst pandemic facing this generation, a disease with deleterious effects on the health and economic systems worldwide. We hypothesize that DC vaccine therapy may provide a potential treatment strategy to help combat COVID-19. Cancer patients are at the top of the vulnerable population owing to their immune-compromised status. In this review, we discuss DC vaccine therapy in the light of the body's immunity, cancer, and newly emerging infections such as COVID-19 in hopes of better-customized treatment options for patients with multiple comorbidities.

Novel molecular mechanisms underlying the ameliorative effect of N-acetyl-L-cysteine against ϒ-radiation-induced premature ovarian failure in rats.

Radiotherapy represents a critical component in cancer treatment. However, premature ovarian failure (POF) is a major hurdle of deleterious off-target effects in young females, which, therefore, call for an effective radioprotective agent. The present study aimed to explore the molecular mechanism underlying the protective effects of N-acetyl-L-cysteine (NAC) against γ-radiation-provoked POF. Immature female Sprague-Dawley rats were orally-administered NAC (50 mg/kg) and were exposed to a single whole-body dose of 3.2 Gy ϒ-radiation. NAC administration remarkably reversed abnormal serum estradiol and anti-Müllerian hormone levels by 73% and 40%, respectively while ameliorating the histopathological and ultrastructural alterations-triggered by γ-radiation. Mechanistically, NAC alleviated radiation-induced oxidative damage through significantly increased glutathione peroxidase activity by 102% alongside with decreasing NADPH oxidase subunits (p22 and NOX4) gene expressions by 48% and 38%, respectively compared to the irradiated untreated group. Moreover, NAC administration achieved its therapeutic effect by inhibiting ovarian apoptosis-induced by radiation through downregulating p53 and Bax levels by 33% and 16%, respectively while increasing the Bcl-2 mRNA expression by 135%. Hence, the Bax/Bcl2 ratio and cytochrome c expression were subsequently reduced leading to decreased caspase 3 activity by 43%. Importantly, the anti-apoptotic property of NAC could be attributed to inactivation of MAPK signaling molecules; p38 and JNK, and enhancement of the ovarian vascular endothelial growth factor (VEGF) expression. Taken together, our results suggest that NAC can inhibit radiotherapy-induced POF while preserving ovarian function and structure through upregulating VEGF expression and suppressing NOX4/MAPK/p53 apoptotic signaling.

Tuning mTORC1 activity dictates the response of acute myeloid leukemia to LSD1 inhibition.

Lysine specific demethylase-1 (LSD1) has been shown to be critical in acute myeloid leukemia (AML) pathogenesis and this has led to the development of LSD1 inhibitors (LSD1i) which are currently tested in clinical trials. Nonetheless, preclinical studies reported that AML cells frequently exhibit intrinsic resistance to LSD1 inhibition, and the molecular basis for this phenomenon is largely unknown. We explored the potential involvement of mammalian target of rapamycin (mTOR) in mediating the resistance of leukemic cells to LSD1i. Strikingly, unlike sensitive leukemias, mTOR complex 1 (mTORC1) signaling was robustly triggered in resistant leukemias following LSD1 inhibition. Transcriptomic, chromatin immunoprecipitation and functional studies revealed that insulin receptor substrate 1(IRS1)/extracellular-signal regulated kinases (ERK1/2) signaling critically controls LSD1i induced mTORC1 activation. Notably, inhibiting mTOR unlocked the resistance of AML cell lines and primary patient-derived blasts to LSD1i both in vitro and in vivo In conclusion, mTOR activation might act as a novel pro-survival mechanism of intrinsic as well as acquired resistance to LSD1i, and combination regimens co-targeting LSD1/mTOR could represent a rational approach in AML therapy.

Preclinical models of breast cancer: Two-way shuttles for immune checkpoint inhibitors from and to patient bedside.

The Food and Drug Administration has lately approved atezolizumab, anti-programmed death ligand 1 (PD-L1), to be used together with nanoparticle albumin-bound (nab) paclitaxel in treating patients with triple negative breast cancer (BC) expressing PD-L1. Nonetheless, immune checkpoint inhibitors (ICIs) are still challenged by the resistance and immune-related adverse effects evident in a considerable subset of treated patients without conclusive comprehension of the underlying molecular basis, biomarkers and tolerable therapeutic regimens capable of unleashing the anti-tumour immune responses. Stepping back to preclinical models is thus inevitable to address these inquiries. Herein, we comprehensively review diverse preclinical models of BC exploited in investigating ICIs underscoring their pros and cons as well as the learnt and awaited lessons to allow full exploitation of ICIs in BC therapy.

Chemotherapy and cognition: comprehensive review on doxorubicin-induced chemobrain.

Chemobrain refers to a common sequela experienced by a substantial subset of cancer patients exposed to chemotherapeutic treatment, a phenomenon that dramatically deteriorates the survivors' quality of life and prevents them from restoring their pre-cancer life. This review is intended to address the current knowledge regarding the mechanisms underlying the pathophysiology of the chemobrain phenomenon, with special focus on the antineoplastic agent ''doxorubicin'', which has been shown to be implicated in strenuous central neurotoxicity despite being-almost entirely-peripherally confined. Moreover, the assessment of the post-chemotherapy cognitive impairment in both human and animal subjects, and the potential pharmacotherapy and behavioral intervention strategies are reviewed.

Mechanistic approach of the inhibitory effect of chrysin on inflammatory and apoptotic events implicated in radiation-induced premature ovarian failure: Emphasis on TGF-ß/MAPKs signaling pathway.

Radiotherapy is one of the most relevant treatment modalities for various types of malignancies. However, it causes premature ovarian failure (POF) and subsequent infertility in women of reproductive age; hence urging the development of effective radioprotective agents. Chrysin, a natural flavone, possesses several pharmacological activities owing to its antioxidant, anti-inflammatory and anti-apoptotic properties. Therefore, the aim of this study was to investigate the efficacy of chrysin in limiting γ-radiation-mediated POF and to elucidate the underlying molecular mechanisms. Immature female Sprague-Dawley rats were subjected to a single dose of γ-radiation (3.2 Gy) and/or treated with chrysin (50 mg/kg) once daily for two weeks before and three days post-irradiation. Chrysin prevented the radiation-induced ovarian dysfunction by restoring estradiol levels, preserving the normal ovarian histoarchitecture and combating the follicular loss. Eelectron microscopic analysis showed that the disruption of ultrastructure components due to radiation exposure was hampered by chrysin administration. Mechanistically, chrsyin was able to reduce the levels of the inflammatory markers NF-κB, TNF-α, iNOS and COX-2 in radiation-induced ovarian damage. Chrysin also exhibited potent anti-apoptotic effects against radiation-induced cell death by downregulating the expression of cytochrome c and caspase 3. Radiation obviously induced upregulation of TGF-ß protein with subsequent phospholyration and hence activation of downstream mitogen-activated protein kinases (MAPKs); p38 and JNK. Notably, administration of chrysin successfully counteracted these effects. These findings revealed that chrysin may be beneficial in ameliorating radiation-induced POF, predominantly via downregulating TGF-ß/MAPK signaling pathways leading subsequently to hindering inflammatory and apoptotic signal transduction pathways implicated in POF.

Serum sclerostin and irisin as predictive markers for atherosclerosis in Egyptian type II diabetic female patients: A case control study.

Diabetes mellitus represents a major independent risk factor for developing fatal cardiovascular diseases (CVDs) presumably through accelerating atherosclerosis; the underlying cause of most CVDs. Notably, this relative risk is reported to be higher in women than men. Endeavors directed towards identifying novel reliable predictive biomarkers are immensely thereby urged to improve the long-term outcome in these diabetic female patients. Sclerostin (SOST) is a Wnt signaling antagonist whereas irisin is a muscle-derived factor released after exercising which enhances browning of white adipose tissue. Emerging lines of evidence hint at potential crosstalk between them and CVDs. The present study aimed to assess the serum levels of SOST and irisin in Egyptian type 2 diabetic (T2DM) female patients with and without atherosclerosis and explore the possible relationship between both markers and other studied parameters among the studied cohorts. In this case-control study, 69 female subjects were enrolled; 39 type 2 diabetes patients with atherosclerosis (T2DM+ATHR), 22 type 2 diabetes patients without atherosclerosis (T2DM-ATHR) and 8 healthy controls. Their serum levels of SOST and irisin were assessed using ELISA. Significant increase in SOST levels were found in T2DM+ATHR compared to T2DM-ATHR and control (259.9 ±17.98 vs. 165.8±13.12 and 142.0±13.31 pg/mL respectively, P<0.001). Conversely, irisin levels were significantly lower in T2DM+ATHR (P<0.001) and T2DM-ATHR (P<0.01) compared to the control group (32.91±2.545 and 58.55±13.19 vs. 473.6±112.7 pg/mL). Interestingly, significant correlations between the levels of SOST and both irisin and fasting blood glucose were noticed in T2DM+ATHR group (r = 0.3754 and 0.3381 respectively, P<0.05). In conclusion, to the best of our knowledge, this study is the first to demonstrate the correlation between SOST and irisin levels in atherosclerotic T2DM female patients implying their potential implication in diabetic cardiovascular pathophysiology and supporting their use as reliable diagnostic/prognostic biomarkers for monitoring and preventing CVDs progression of T2DM female patients.

Comparative study of anti-VEGF Ranibizumab and Interleukin-6 receptor antagonist Tocilizumab in Adjuvant-induced Arthritis.

Although the precise etiology of Rheumatoid arthritis (RA) remains obscure, heightened immune response is thought to play a vital role in provoking joint inflammation and bone erosion. This study aims at comparatively evaluating the effects of two monoclonal antibodies Ranibizumab (RANI) as anti-VEGF antibody and Tocilizumab (TCZ) as interleukin-6 receptor (IL-6R) antagonist, against adjuvant induced arthritis in rats. CFA-induced arthritic rats were treated for three consecutive weeks with Methotrexate (MTX), TCZ and RANI monotherapy. Clinical assessment of RA, bone erosion, inflammatory, angiogenic and apoptotic markers were determined to assess the anti-arthritic effect. Liver enzymes and histopathological examination of liver and spleen were assessed to evaluate the toxicity profile of the tested therapeutic agents. MTX, TCZ and RANI monotherapy significantly enhanced the anti-arthritic parameters in comparison with the Complete Freund's Adjuvant (CFA)-induced arthritic rats through significant reduction of ankle and paw swelling. Also, they significantly reduced inflammatory, angiogenic and apoptotic markers. Importantly, Ranibizumab showed better effect than the standard anti-rheumatic drugs Methotrexate (MTX) or Tocilizumab (TCZ) in bone protection and cartilage health; hence proves to be a promising new therapeutic agent for RA.

Surmounting the resistance against EGFR inhibitors through the development of thieno[2,3-d]pyrimidine-based dual EGFR/HER2 inhibitors.

In light of the emergence of resistance against the currently available EGFR inhibitors, our study focuses on tackling this problem through the development of dual EGFR/HER2 inhibitors with improved enzymatic affinities. Guided by the binding mode of the marketed dual EGFR/HER2 inhibitor, Lapatinib, we proposed the design of dual EGFR/HER2 inhibitors based on the 6-phenylthieno[2,3-d]pyrimidine as a core scaffold and hinge binder. After two cycles of screening aiming to identify the optimum aniline headgroup and solubilizing group, we eventually identified 27b as a dual EGFR/HER2 inhibitor with IC50 values of 91.7 nM and 1.2 µM, respectively. Notably, 27b dramatically reduced the viability of various patient-derived cancer cells preferentially overexpressing EGFR/HER2 (A431, MDA-MBA-361 and SKBr3 with IC50 values of 1.45, 3.5 and 4.83 µM, respectively). Additionally, 27b efficiently thwarted the proliferation of lapatinib-resistant human non-small lung carcinoma (NCI-H1975) cells, harboring T790 M mutation, with IC50 of 4.2 µM. Consistently, 27b significantly blocked EGF-induced EGFR activation and inactivated its downstream AKT/mTOR/S6 signalling pathway triggering apoptotic cell death in NCI-H1975 cells. The present study presents a promising candidate for further design and development of novel EGFR/HER2 inhibitors capable of overcoming EGFR TKIs resistance.