Design, synthesis and biological evaluation of 4-aniline-thieno[2,3-d]pyrimidine derivatives as MNK1 inhibitors against renal cell carcinoma and nasopharyngeal carcinoma

Novel small molecule inhibitors targeting renal cell carcinoma: Status, challenges, future directions

Renal cell carcinoma (RCC) is the most common renal malignancy with a rapidly increasing morbidity and mortality rate gradually. RCC has a high mortality rate and an extremely poor prognosis. Despite numerous treatment strategies, RCC is resistant to conventional radiotherapy and chemotherapy. In addition, the limited clinical efficacy and inevitable resistance of multiple agents suggest an unmet clinical need. Therefore, there is an urgent need to develop novel anti-RCC candidates. Nowadays many promising results have been achieved with the development of novel small molecule inhibitors against RCC. This paper reviews the recent research progress of novel small molecule inhibitors targeting RCC. It is focusing on the structural optimization process and conformational relationships of small molecule inhibitors, as well as the potential mechanisms and anticancer activities for the treatment of RCC. To provide a theoretical basis for promoting the clinical translation of novel small molecule inhibitors, we discussed their application prospects and future development directions. It could be capable of improving the clinical efficacy of RCC and improving the therapy resistance for RCC.

MNK, mTOR or eIF4E-selecting the best anti-tumor target for blocking translation initiation

Overexpression of eIF4E is common in patients with various solid tumors and hematologic cancers. As a potential anti-cancer target, eIF4E has attracted extensive attention from researchers. At the same time, mTOR kinases inhibitors and MNK kinases inhibitors, which are directly related to regulation of eIF4E, have been rapidly developed. To explore the optimal anti-cancer targets among MNK, mTOR, and eIF4E, this review provides a detailed classification and description of the anti-cancer activities of promising compounds. In addition, the structures and activities of some dual-target inhibitors are briefly described. By analyzing the different characteristics of the inhibitors, it can be concluded that MNK1/2 and eIF4E/eIF4G interaction inhibitors are superior to mTOR inhibitors. Simultaneous inhibition of MNK and eIF4E/eIF4G interaction may be the most promising anti-cancer method for targeting translation initiation.

Precision medicine in nasopharyngeal carcinoma: comprehensive review of past, present, and future prospect

Nasopharyngeal carcinoma (NPC) is an aggressive malignancy with high propensity for lymphatic spread and distant metastasis. It is prominent as an endemic malignancy in Southern China and Southeast Asia regions. Studies on NPC pathogenesis mechanism in the past decades such as through Epstein Barr Virus (EBV) infection and oncogenic molecular aberrations have explored several potential targets for therapy and diagnosis. The EBV infection introduces oncoviral proteins that consequently hyperactivate many promitotic pathways and block cell-death inducers. EBV infection is so prevalent in NPC patients such that EBV serological tests were used to diagnose and screen NPC patients. On the other hand, as the downstream effectors of oncogenic mechanisms, the promitotic pathways can potentially be exploited therapeutically. With the apparent heterogeneity and distinct molecular aberrations of NPC tumor, the focus has turned into a more personalized treatment in NPC. Herein in this comprehensive review, we depict the current status of screening, diagnosis, treatment, and prevention in NPC. Subsequently, based on the limitations on those aspects, we look at their potential improvements in moving towards the path of precision medicine. The importance of recent advances on the key molecular aberration involved in pathogenesis of NPC for precision medicine progression has also been reported in the present review. Besides, the challenge and future outlook of NPC management will also be highlighted.

Ecofriendly Synthesis of Formamidine Derivatives Catalyzed by Al-MCM- 41 Mesoporous Materials

Abstract:

Formamidine derivatives have been synthesized in excellent yields at room temperature from primary amine and N,N-dimethylformamide dimethylacetal (DMF-DMA) in the presence of a catalytic amount of Al-MCM-41 synthesized from natural bentonite as silica and aluminum source. The advantages of this method are the use of a cheap, stable, non-toxic, and readily available catalyst, easy work-up, improved yields, and solvent-free conditions.

Update on the Development of MNK Inhibitors as Therapeutic Agents

Mitogen-activated protein kinase-interacting kinases 1 and 2 (MNK1/2) represent a central class of enzymes that are activated by extracellular signal-regulated kinase (ERK) or p38 mitogen-activated protein (MAP) kinases. MNK1 and MNK2 coordinate cellular signaling, control production of inflammatory chemokines, and regulate cell proliferation and survival. MNK1/2 are referred to as serine/threonine kinases as they phosphorylate serine or threonine residues on their substrates. Upon activation, MNK1/2 phosphorylate eukaryotic translation initiation factor 4E (eIF4E) at Ser209, which in turn initiates ribosome assembly and protein translation. Deleterious overexpression of MNK1/2 and/or eIF4E have been reported in several diseases including cancers, neurological disorders, autism, and inflammation. Recently, there have been intense efforts toward the development of potent and selective inhibitors of MNK1/2 in both academia and industry. Herein, we review the current understanding of the structural and biological aspects of MNK1/2 and provide an update of pharmacological inhibitors of MNK1/2 including candidates in clinical trials.

Renal cell carcinoma therapy: Current and new drug candidates

Renal cell carcinoma (RCC) is the most common and lethal tumor of the urological system. Curative treatment of localized RCC includes nephrectomy, radio-ablation, and active surveillance, whereas metastatic RCC (mRCC) requires a combination of surgery and systemic therapy. Response to conventional therapy is limited but, recently, many novel therapies for mRCC have emerged, including targeted therapies and new immunotherapeutic agents. Nevertheless, development of resistance and limited durable responses demand new anticancer candidates with improved selectivity and efficacy. In this review, we summarize recent preclinical studies of novel natural and synthetic compounds to treat RCC, detailing their mechanisms of action and anticancer activities.

Progress in developing MNK inhibitors

The MNKs (mitogen-activated protein kinase-interacting protein kinases) phosphorylate eIF4E (eukaryotic initiation factor 4 E) at serine 209; eIF4E plays an important role in the translation of cytoplasmic mRNAs, all of which possess a 5' 'cap' structure to which eIF4E binds. Elevated levels of eIF4E, p-eIF4E and/or the MNK protein kinases have been found in many types of cancer, including solid tumors and leukemia. MNKs also play a role in metabolic disease. Regulation of the activities of MNKs (MNK1 and MNK2), control the phosphorylation of eIF4E, which in turn has a close relationship with the processes of tumor development, cell migration and invasion, and energy metabolism. MNK knock-out mice display no adverse effects on normal cells or phenotypes suggesting that MNK may be a potentially safe targets for the treatment of various cancers. Several MNK inhibitors or 'degraders' have been identified. Initially, some of the inhibitors were developed from natural products or based on other protein kinase inhibitors which inhibit multiple kinases. Subsequently, more potent and selective inhibitors for MNK1/2 have been designed and synthesized. Currently, three inhibitors (BAY1143269, eFT508 and ETC-206) are in various stages of clinical trials for the treatment of solid cancers or leukemia, either alone or combined with inhibitors of other protein kinase. In this review, we summarize the diverse MNK inhibitors that have been reported in patents and other literature, including those with activities in vitro and/or in vivo.

Advances in targeted therapy mainly based on signal pathways for nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial carcinoma of the head and neck region which mainly distributes in southern China and Southeast Asia and has a crucial association with the Epstein-Barr virus. Based on epidemiological data, both incidence and mortality of NPC have significantly declined in recent decades grounded on the improvement of living standard and medical level in an endemic region, in particular, with the clinical use of individualized chemotherapy and intensity-modulated radiotherapy (IMRT) which profoundly contributes to the cure rate of NPC patients. To tackle the challenges including local recurrence and distant metastasis in the current NPC treatment, we discussed the implication of using targeted therapy against critical molecules in various signal pathways, and how they synergize with chemoradiotherapy in the NPC treatment. Combination treatment including targeted therapy and IMRT or concurrent chemoradiotherapy is presumably to be future options, which may reduce radiation or chemotherapy toxicities and open new avenues for the improvement of the expected functional outcome for patients with advanced NPC.

Deeping in the Role of the MAP-Kinases Interacting Kinases (MNKs) in Cancer

The mitogen-activated protein kinase (MAPK)-interacting kinases (MNKs) are involved in oncogenic transformation and can promote metastasis and tumor progression. In human cells, there are four MNKs isoforms (MNK1a/b and MNK2a/b), derived from two genes by alternative splicing. These kinases play an important role controlling the expression of specific proteins involved in cell cycle, cell survival and cell motility via eukaryotic initiation factor 4E (eIF4E) regulation, but also through other substrates such as heterogeneous nuclear ribonucleoprotein A1, polypyrimidine tract-binding protein-associated splicing factor and Sprouty 2. In this review, we provide an overview of the role of MNK in human cancers, describing the studies conducted to date to elucidate the mechanism involved in the action of MNKs, as well as the development of MNK inhibitors in different hematological cancers and solid tumors.

Discovery of novel TNNI3K inhibitor suppresses pyroptosis and apoptosis in murine myocardial infarction injury

Myocardial infarction (MI) injury is a highly lethal syndrome that has, until recently, suffered from a lack of clinically efficient targeted therapeutics. The cardiac troponin I interacting kinase (TNNI3K) exacerbates ischemia-reperfusion (IR) injury via oxidative stress, thereby promoting cardiomyocyte death. In this current study, we designed and synthesized 35 novel TNNI3K inhibitors with a pyrido[4,5]thieno[2,3-d] pyrimidine scaffold. In vitro results indicated that some of the inhibitors exhibited sub-micromolar TNNI3K inhibitory capacity and good kinase selectivity, as well as cytoprotective activity, in an oxygen-glucose deprivation (OGD) injury cardiomyocyte model. Furthermore, investigation of the mechanism of the representative derivative compound 6o suggested it suppresses pyroptosis and apoptosis in cardiomyocytes by interfering with p38MAPK activation, which was further confirmed in a murine myocardial infarction injury model. In vivo results indicate that compound 6o can markedly reduce myocardial infarction size and alleviate cardiac tissue damage in rats. In brief, our results provide the basis for further development of novel TNNI3K inhibitors for targeted MI therapy.

Discovery of novel akt1 inhibitor induces autophagy associated death in hepatocellular carcinoma cells

In this study, a series of thieno [2,3-d]pyrimidine derivatives were designed, synthesized and evaluated as novel AKT1 inhibitors. In vitro antitumor assay results showed that compounds 9d-g and 9i potently suppressed the enzymatic activities of AKT1 and potently inhibited the proliferation of HepG2, Hep3B, Huh-7 and SMMC-7721 cancer cell lines. Among these derivatives, the compound 9f demonstrated the best inhibitory activities on AKT1 (IC50 = 0.034 μM) and Huh-7 cell (IC50 = 0.076 μM). A panel of biological assays showed that compound 9f suppressed the cellular proliferation of Huh-7 through Akt/mTOR signaling pathway mediated autophagy mechanism. Furthermore, the antitumor capacity of 9f was validated in the subcutaneous Huh-7 xenograft models. Together, our results demonstrate that a novel small-molecule Akt1 inhibitor induces autophagy associated death in hepatocellular carcinoma, which may afford a potential drug candidate for targeted cancer therapy.

Synthesis of Novel Analogs of Thieno[2,3-d] Pyrimidin-4(3H)-ones as Selective Inhibitors of Cancer Cell Growth

New 2,3-disubstituted thieno[2,3-d]pyrimidin-4(3H)-ones were synthesized via a one-pot reaction from 2H-thieno[2,3-d] [1,3]oxazine-2,4(1H)-diones, aromatic aldehydes, and benzylamine or 4-hydroxylbezylamine. The obtained compounds were tested in vitro for cancer cell growth inhibition. Compound 19 can inhibit all four types of tested cancer cells, i.e., MCF-7, A549, PC-9, and PC-3 cells. Most of the compounds inhibited the proliferation of A549 and MCF-7 cells. Compound 15 exhibited the strongest anti-proliferative effect against A549 cell lines with IC50 values of 0.94 μM, and with no toxicity to normal human liver cells. Its potency was further proved by cell clone formation assay, Hoechst 33258 staining, and evaluation on the effects of apoptosis-related proteins.