Novel pyrazolo[3,4-d]pyrimidines as dual Src/Bcr-Abl kinase inhibitors: Synthesis and biological evaluation for chronic myeloid leukemia treatment

Fyn, Blk, and Lyn kinase inhibitors: A mini-review on medicinal attributes, research progress, and future insights

Fyn, Blk, and Lyn are part of a group of proteins called Src family kinases. They are crucial in controlling cell communication and their response to the growth, changes, and immune system. Blocking these proteins with inhibitors can be a way to treat diseases where these proteins are too active. The primary mode of action of these inhibitors is to inhibit the phosphorylation of Fyn, Blk, and Lyn receptors, which in turn affects how signals pass within the cells. This review shows the structural and functional aspects of Fyn, Blk, and Lyn kinases, highlighting the significance of their dysregulation in diseases such as cancer and autoimmune disorders. The discussion encompasses the design strategies, SAR analysis, and chemical characteristics of effective inhibitors, shedding light on their specificity and potency. Furthermore, it explores the progress of clinical trials of these inhibitors, emphasizing their potential therapeutic applications.

2H-chromene and 7H-furo-chromene derivatives selectively inhibit tumour associated human carbonic anhydrase IX and XII isoforms

Tumour associated carbonic anhydrases (CAs) IX and XII have been recognised as potential targets for the treatment of hypoxic tumours. Therefore, considering the high pharmacological potential of the chromene scaffold as selective ligand of the IX and XII isoforms, two libraries of compounds, namely 2H-chromene and 7H-furo-chromene derivatives, with diverse substitution patterns were designed and synthesised. The structure of the newly synthesised compounds was characterised and their inhibitory potency and selectivity towards human CA off target isoforms I, II and cancer-associated CA isoforms IX and XII were evaluated. Most of the compounds inhibit CA isoforms IX and XII with no activity against the I and II isozymes. Thus, while the potency was influenced by the substitution pattern along the chromene scaffold, the selectivity was conserved along the series, confirming the high potential of both 2H-chromene and 7H-furo-chromene scaffolds for the design of isozyme selective inhibitors.

Sweet Cherry Extract as Permeation Enhancer of Tyrosine Kinase Inhibitors: A Promising Prospective for Future Oral Anticancer Therapies

Although patients would rather oral therapies to injections, the gastrointestinal tract's low permeability makes this method limiting for most compounds, including anticancer drugs. Due to their low bioavailability, oral antitumor therapies suffer from significant variability in pharmacokinetics and efficacy. The improvement of their pharmacokinetic profiles can be achieved by a new approach: the use of natural extracts enriched with polyphenolic compounds that act as intestinal permeability enhancers. Here, we propose a safe sweet cherry extract capable of enhancing oral absorption. The extract was characterized by the HPLC-UV/MS method, evaluated for in vitro antioxidant activity, safety on the Caco-2 cell line, and as a potential permeation enhancer. The sweet cherry extract showed a high antioxidant capacity (ABTS and DPPH assays were 211.74 and 48.65 µmol of Trolox equivalent/g dried extract, respectively), high content of polyphenols (8.44 mg of gallic acid per gram of dry extract), and anthocyanins (1.80 mg of cyanidin-3-glucoside equivalent per g of dry extract), reassuring safety profile (cell viability never lower than 98%), and a significant and fully reversible ability to alter the integrity of the Caco-2 monolayer (+81.5% of Lucifer yellow permeability after 2 h). Furthermore, the ability of the sweet cherry extract to improve the permeability (Papp) and modify the efflux ratio (ER) of reference compounds (atenolol, propranolol, and dasatinib) and selected pyrazolo[3,4-d]pyrimidine derivatives was investigated. The obtained results show a significant increase in apparent permeability across the Caco-2 monolayer (tripled and quadrupled in most cases), and an interesting decrease in efflux ratio when compounds were co-incubated with sweet cherry extract.

Acute Basophilic Leukemia Arising from Chronic Myeloid Leukemia with +8, I(17q)(q10) and der(22)t(9;22) After Imatinib Therapy

Acute basophilic leukemia (ABL) arising from chronic myeloid leukemia (CML) with abundant mast cells (MCs), coexisting with a complex karyotype is rare. Here, we report an 81-year-old man admitted to our hospital with a history of ABL. He was diagnosed with CML in the chronic phase in January 2018, and Imatinib was used at a daily dose of 400mg. Then, transformation to ABL with abundant MCs in the bone marrow and complex karyotypes including 48,XY, trisomy 8 (+8), isochromosome 17(q10) [i(17)(q10)], and derivative chromosome 22 t(9;22) [der(22)t(9;22)] were discovered simultaneously in January 2022. In conclusion, the increased number of MCs in our case is a reminder that they might play an important role in the prognosis of CML and trigger the development of complex karyotypes. Moreover, this is the first case report of ABL arising from CML with abundant MCs, coexisting with 48,XY, +8, i(17)(q10), and der(22)t(9;22), during Imatinib treatment. Further studies are needed to better characterize this rare condition.

Identification and Biological Characterization of the Pyrazolo[3,4-d]pyrimidine Derivative SI388 Active as Src Inhibitor

Src is a non-receptor tyrosine kinase (TK) whose involvement in cancer, including glioblastoma (GBM), has been extensively demonstrated. In this context, we started from our in-house library of pyrazolo[3,4-d]pyrimidines that are active as Src and/or Bcr-Abl TK inhibitors and performed a lead optimization study to discover a new generation derivative that is suitable for Src kinase targeting. We synthesized a library of 19 compounds, 2a-s. Among these, compound 2a (SI388) was identified as the most potent Src inhibitor. Based on the cell-free results, we investigated the effect of SI388 in 2D and 3D GBM cellular models. Interestingly, SI388 significantly inhibits Src kinase, and therefore affects cell viability, tumorigenicity and enhances cancer cell sensitivity to ionizing radiation.