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Verapamil, a calcium antagonist, inhibited both experimental (IV inoculation of tumor cells) and spontaneous metastasis (SC inoculation) of the highly metastatic B16 melanoma and colon adenocarcinoma 26 cell lines. Verapamil treatment resulted in a maximum 80% inhibition of metastases, the degree of inhibition varying among the different metastatic systems. Verapamil inhibited platelet aggregation induced by these tumor cell lines, the patterns of inhibition being different for B16 melanoma and colon adenocarcinoma. The inhibition of platelet aggregation induced by tumor cells is proposed as a mechanism by which the calcium antagonist exerts its antimetastatic effect. These results, together with our previous findings that calcium antagonists can increase the cytotoxicity of drugs in tumor cells with induced or inherent drug resistance by inhibiting outward transport of the drug, indicate that calcium antagonists have potential as a new class of adjuvant agents in the field of cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Abstract Background Phosphoproteins play important roles in a vast series of biological processes. Recent proteomic technologies offer the comprehensive analyses of phosphoproteins. Recently, we demonstrated that surface-enhanced laser desorption/ionization time of flight mass (SELDI-TOF MS) would detect phosphoproteins quantitatively, which was a new application of SELDI-TOF MS. Results We combined immobilized metal affinity chromatography (IMAC) with SELDI-TOF MS. After SELDI-TOF MS analysis of IMAC-enrichment phosphoproteins from A549 cancer cells, a series of protein peaks at 12.9, 12.8, 12.7 and 12.6 kDa was obtained in a mass spectrum. The peak intensities of these proteins decreased after a phosphatase treatment and, interestingly, they also decreased when the cells were pre-treated with a novel phosphatidylinositol 3-kinase (PI3K) inhibitor, ZSTK474, suggesting that these proteins were ZSTK474-sensitive phosphoproteins. Identity of the phosphoproteins, which were predicted as the multi-phosphorylated forms of 4E-binding protein 1 (4E-BP1) with the aid of TagIdent algorithm, was confirmed by immunoprecipitation and subsequent SELDI-TOF MS analysis. 4E-BP1 is a downstream component of the PI3K/Akt/mTOR pathway and it regulates protein synthesis. We also investigated the effect of ZSTK474 on 4E-BP1 phosphorylation using phospho-specific antibodies. ZSTK474, which have little inhibitory activity for mTOR, inhibited phosphorylation of Ser65, Thr70 and Thr37/46 in 4E-BP1. In contrast, rapamycin, an inhibitor of mTOR, blocked phosphorylation only of Ser65 and Thr70. These results suggest that ZSTK474 and rapamycin inhibited the phosphorylation of 4E-BP1 in a different manner. Conclusion We identified a group of ZSTK474-sensitive phosphoproteins as the multi-phosphorylated form of 4E-BP1 by combining IMAC, SELDI-TOF MS and antibodies.

As accumulating evidences suggest close involvement of phosphatidylinositol 3-kinase (PI3K) in various diseases particularly cancer, considerable competition occurs in development of PI3K inhibitors. Consequently, novel PI3K inhibitors such as ZSTK474, GDC-0941 and NVP-BEZ235 have been developed. Even though all these inhibitors were reported to inhibit class I PI3K but not dozens of protein kinases, whether they have different molecular targets remained unknown. To investigate such molecular target specificity, we have determined the inhibitory effects of these novel inhibitors together with classical PI3K inhibitor LY294002 on PI3K superfamily (including classes I, II, and III PI3Ks, PI4K and PI3K-related kinases) by using several novel non-radioactive biochemical assays. As a result, ZSTK474 and GDC-0941 indicated highly similar inhibition profiles for PI3K superfamily, with class I PI3K specificity much higher than NVP-BEZ235 and LY294002. We further investigated their growth inhibition effects on JFCR39, a human cancer cell line panel which we established for molecular target identification, and analysed their cell growth inhibition profiles (fingerprints) by using COMPARE analysis programme. Interestingly, we found ZSTK474 exhibited a highly similar fingerprint with GDC-0941 (r=0.863), more similar than with that of either NVP-BEZ235 or LY294002, suggesting that ZSTK474 shares more in molecular targets with GDC-0941 than with either of the other two PI3K inhibitors, consistent with the biochemical assay result. The biological implication of the difference in molecular target specificity of these PI3K inhibitors is under investigation. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to determine whether the Fracture Risk Assessment Tool (FRAX ® ) is useful in assessing the criteria for the initiation of pharmacotherapy for primary osteoporosis based on the current diagnostic criteria in Japan., Materials and Methods: We enrolled 614 patients aged ≥ 40 years (average, 77.0 years) who were eligible for primary osteoporosis evaluation. Bone mineral density measurements of the lumbar spine, total hip, and femoral neck using ALPHYS LF (FUJIFILM, Tokyo, Japan) and imaging studies involving the lumbar spine were obtained and the FRAX ® scores of each patient were calculated with and without the T-score of the femoral neck. The receiver operating characteristic curve analysis method was used to calculate the cut-off FRAX ® scores with reference to the criteria for initiating pharmacotherapy for osteoporosis; the accuracies of both FRAX ® scores were compared., Results: The FRAX ® score calculated with the T-score was more accurate for hip fracture risk assessment [cut-off value 5.5%; the area under the curve (AUC) 0.946] than for major osteoporotic fracture risk assessment (cut-off value 17.0%; AUC 0.924) in judging the criteria (p = 0.001). Conversely, the FRAX ® score calculated without the T-score was equally accurate for hip fracture risk assessment (AUC 0.796) and major osteoporotic fracture risk assessment (AUC 0.806) (p = 0.23)., Conclusion: The FRAX ® score can accurately assess the criteria for initiating pharmacotherapy for primary osteoporosis based on the current Japanese diagnostic criteria, especially when the T-score is used., (© 2022. The Japanese Society Bone and Mineral Research.)

Background The Japanese Pharmaceuticals and Medical Devices Agency (PMDA) was established in 2004. Since then, various pieces of legislation, notices, and guidelines have been issued, and the regulatory approval pathways for domestic drugs have been diversified. However, the effects of these measures have not been fully examined. We examined the impact of these measures on the approval of antineoplastic drugs and the design of pivotal clinical trials for efficacy assessment by the PMDA. Methods We collected data on the antineoplastic drugs approved by the PMDA in fiscal years 2004-2019. We extracted the approval review pathways and the pivotal clinical trial designs from the PMDA review reports, and analyzed them to identify patterns. Results In total, 387 indications in oncology were approved by the PMDA in fiscal years 2004-2019, or 365 indications excluding multiple regulatory pathways. The number of approved indications generally increased year on year (p < 0.001). The largest number of approved indications was under the Orphan Drug Designation (31%, 114/365) and this continues to increase (p < 0.001). In the 288 indications for which clinical trial data were submitted for review, the pivotal clinical trial designs changed significantly (p < 0.001) after the guideline on clinical evaluation for antineoplastic drugs was revised in 2006. Conclusion The number of indications in oncology approved by the PMDA has been increasing over the past 16 years, alongside changes in regulatory pathways. The 2006 guideline on clinical evaluation had a particular impact on pivotal clinical trial designs., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The emergence of acquired resistance is a major concern associated with molecularly targeted kinase inhibitors. The C797S mutation in the epidermal growth factor receptor (EGFR) confers resistance to osimertinib, a third-generation EGFR-tyrosine kinase inhibitor (EGFR-TKI). We report that the derivatization of the marine alkaloid topoisomerase inhibitor lamellarin N provides a structurally new class of EGFR-TKIs. One of these, lamellarin 14, is effective against the C797S mutant EGFR. Bioinformatic analyses revealed that the derivatization transformed the topoisomerase inhibitor-like biological activity of lamellarin N into kinase inhibitor-like activity. Ba/F3 and PC-9 cells expressing the EGFR in-frame deletion within exon 19 (del ex19)/T790M/C797S triple-mutant were sensitive to lamellarin 14 in a dose range similar to the effective dose for cells expressing EGFR del ex19 or del ex19/T790M. Lamellarin 14 decreased the autophosphorylation of EGFR and the downstream signaling in the triple-mutant EGFR PC-9 cells. Furthermore, intraperitoneal administration of 10 mg/kg lamellarin 14 for 17 days suppressed tumor growth of the triple-mutant EGFR PC-9 cells in a mouse xenograft model using BALB/c nu/nu mice. Thus, lamellarin 14 serves as a novel structural backbone for an EGFR-TKI that prevents the development of cross-resistance against known drugs in this class., (© 2021 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)