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Controlling RAS mutant cancer progression remains a significant challenge in developing anticancer drugs. Whereas Ras G12C-covalent binders have received clinical approval, the emergence of further mutations, along with the activation of Ras-related proteins and signals, has led to resistance to Ras binders. To discover novel compounds to overcome this bottleneck, we focused on the concurrent and sustained blocking of two major signaling pathways downstream of Ras. To this end, we synthesized 25 drug-drug conjugates (DDCs) by combining the MEK inhibitor trametinib with Akt inhibitors using seven types of linkers with structural diversity. The DDCs were evaluated for their cell permeability/accumulation and ability to inhibit proliferation in RAS-mutant cell lines. A representative DDC was further evaluated for its effects on signaling proteins, induction of apoptosis-related proteins, and the stability of hepatic metabolic enzymes. These in vitro studies identified a series of DDCs, especially those containing a furan-based linker, with promising properties as agents for treating RAS-mutant cancers. Additionally, in vivo experiments in mice using the two selected DDCs revealed prolonged half-lives and anticancer efficacies comparable to those of trametinib. The PK profiles of trametinib and the Akt inhibitor were unified through the DDC formation. The DDCs developed in this study have potential as drug candidates for the broad inhibition of RAS-mutant cancers., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Corresponding author YW used to work for the pharmaceutical division of JT Incorporation that had originally discovered trametinib as JTP-74057. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Drug resistance limits the efficacy of chemotherapy and targeted cancer treatments, calling for the identification of druggable targets to overcome it. Here we show that the mitochondria-shaping protein Opa1 participates in resistance against the tyrosine kinase inhibitor gefitinib in a lung adenocarcinoma cell line. Respiratory profiling revealed that oxidative metabolism was increased in this gefitinib-resistant lung cancer cell line. Accordingly, resistant cells depended on mitochondrial ATP generation, and their mitochondria were elongated with narrower cristae. In the resistant cells, levels of Opa1 were increased and its genetic or pharmacological inhibition reverted the mitochondrial morphology changes and sensitized them to gefitinib-induced cytochrome c release and apoptosis. In vivo, the size of gefitinib-resistant lung orthotopic tumors was reduced when gefitinib was combined with the specific Opa1 inhibitor MYLS22. The combo gefitinib-MYLS22 treatment increased tumor apoptosis and reduced its proliferation. Thus, the mitochondrial protein Opa1 participates in gefitinib resistance and can be targeted to overcome it., (© 2023. The Author(s).)

JQ1 disrupts the binding of bromodomain and extra-terminal (BET) family of proteins to acetylated histones, modulates the expression of various genes, and inhibits the proliferation of cancer cells. We established two JQ1-resistant sublines from human colorectal cancer HCT116 cells. These resistant cells showed an 8- to 9-fold higher resistance to JQ1, and a 2- to 4-fold higher resistance to various anti-cancer agents, such as doxorubicin, etoposide, mitoxantrone, SN-38, cisplatin, and methotrexate than the parental HCT116 cells. The JQ1-resistant cells expressed higher levels of TRAF2 and NCK-interacting protein kinase (TNIK), cyclin D1 (CCND1), cyclin E1 (CCNE1), and their corresponding mRNAs than the parental cells. TNIK is a regulator of Wnt/β-catenin signaling and is known to transactivate CCND1. Transient transfection of HCT116 cells with a TNIK expression plasmid resulted in the upregulation of cyclin D1, cyclin E1, and their corresponding mRNAs, as well as an increase in CCNE1 promoter activity. Furthermore, luciferase assay revealed that the JQ1-resistant cells showed high CCNE1 promoter activity. These results suggest that TNIK also transactivates CCNE1. Three stable TNIK transfectant clones of HEK293 cells expressed 1.5- to 2-fold higher levels of TNIK, cyclin D1, and cyclin E1 than the parental cells. The 293/TNIK-6 cells, which expressed the highest level of TNIK among the transfectants, showed a 2.3-fold higher resistance to JQ1 than the parental cells. These results suggest the possible involvement of TNIK in cellular resistance to JQ1., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The patient was a 67-year-old male who had been treated for several years with 150 mg fluvoxamine maleate due to depression. He visited our hospital with primary symptoms of swelling of the right upper extremity and dyspnea in August, XXXX. As a result of examinations, he was diagnosed with stage IIIB extended small cell lung cancer(T4N3M0). One course of carboplatin/etoposide(CBDCA/VP-16)therapy was started on October 1. Since the tumor size was reduced, thoracic effusion disappeared, and superior vena cava syndrome was alleviated, the therapy was changed to cisplatin/irinotecan (CDDP/CPT-11)on October 23, and the 3rd course was initiated on November 22. Anxiety and tremor appeared on the 4th day of the 3rd course and because they were exacerbated, and myoclonus appeared, a diagnosis of serotonin syndrome was made on the 38th day, and the administration of fluvoxamine maleate was discontinued. The symptoms were alleviated after the discontinuation, and the 4th course could be implemented. In this patient, serotonin syndrome was considered to have been induced by serotonin secretion promoted by the CDDP administration, and by serotonin in the brain increasing abnormally due to the SSRI.

Background: The phosphatidylinositol 3-kinase (PI3K) pathway plays an important role in multiple myeloma (MM), a blood cancer associated with uncontrolled proliferation of bone marrow plasma cells. This study aimed to develop a robust clinical pharmacodynamic (PD) assay to measure the on-target PD effects of the selective PI3K inhibitor GDC-0941 in MM patients., Methods: We conducted an in vitro drug wash-out study to evaluate the feasibility of biochemical approaches in measuring the phosphorylation of S6 ribosomal protein (S6), one of the commonly used PD markers for PI3K pathway inhibition. We then developed a 7-color phospho-specific flow cytometry assay, or phospho flow assay, to measure the phosphorylation state of intracellular S6 in bone marrow aspirate (BMA) and peripheral blood (PB). Integrated mean fluorescence intensity (iMFI) was used to calculate fold changes of phosphorylation. Assay sensitivity was evaluated by comparing phospho flow with Meso Scale Discovery (MSD) and immunohistochemistry (IHC) assays. Finally, a sample handling method was developed to maintain the integrity of phospho signal during sample shipping and storage to ensure clinical application., Results: The phospho flow assay provided single-cell PD monitoring of S6 phosphorylation in tumor and surrogate cells using fixed BMA and PB, assessing pathway modulation in response to GDC-0941 with sensitivity similar to that of MSD assay. The one-shot sample fixation and handling protocol herein demonstrated exceptional preservation of protein phosphorylation. In contrast, the IHC assay was less sensitive in terms of signal quantification while the biochemical approach (MSD) was less suitable to assess PD activities due to the undesirable impact associated with cell isolation on the protein phosphorylation in tumor cells., Conclusions: We developed a robust PD biomarker assay for the clinical evaluation of PI3K inhibitors in MM, allowing one to decipher the PD response in a relevant cell population. To our knowledge, this is the first report of an easily implemented clinical PD assay that incorporates an unbiased one-shot sample handling protocol, all (staining)-in-one (tube) phospho flow staining protocol, and an integrated modified data analysis for PD monitoring of kinase inhibitors in relevant cell populations in BMA and PB. The methods described here ensure a real-time, reliable and reproducible PD readout, which can provide information for dose selection as well as help to identify optimal combinations of targeted agents in early clinical trials.

From March 1992 to October 1997, a total of 38 patients with histologically proven esophageal cancer received combination therapy of daily low-dose cisplatin (CDDP) and radiation therapy. The clinical stages (UICC 1997) were I in 3, IIA,B in 13, III in 13, and IVA in 9 patients. CDDP (5 mg/m2) was administered intravenously with 100 ml saline 30 min before each irradiation from Monday to Friday. All patients received at least 60 Gy of radiation therapy. The average number of CDDP administrations was 23, and the mean total CDDP dose was 115 mg/m2. Of the 38 patients, 14 patients completed full course of chemoradiation therapy. The overall survival rates at 1, 2, and 5 years were 51%, 19%, and 8%, respectively. The median survival period was 12 months. The objective response rate was 82% with 11 (29%) CR. Survival of the stage II-IVA patients who received daily low-dose CDDP and radiation therapy was a little better than that of historical control patients who were treated by radiation therapy alone. Most of the patients experienced nausea. Grade 3 esophagitis was observed in two (5%) patients. Grade 4 leukocytopenia and thorobocytopenia were observed in one (3%) and two (5%) of the patients, respectively. Except for leukocytopenia (18%), frequencies of toxicity of grade 3 or more were less than 10%. Although the results indicate that daily low-dose CDDP combined with radiation therapy may slightly improve the survival of esophageal cancer patients with acceptable toxicity, further efforts should be made to optimize clinical trial protocols. Escalation of daily CDDP dose should be considered to obtain a more effective radiosensitizing effect.

Curcumin, a natural phenolic compound, is gaining importance as a free radical scavenger. This study was undertaken to investigate the modulatory effects of curcumin on the chromosomal damage induced by the antitumoral doxorubicin (DXR), a known free radical generator, in Chinese hamster ovary cells in culture. Cells were treated with three concentrations of curcumin (2.5, 5, or 10 microg/ml) and then treated with DXR (1.0 microg/ml) during different phases of the cell cycle. The results show that curcumin induces chromosomal damage in CHO at the highest concentration when compared to the untreated control. Neither treatment with curcumin shows a reduction in the clastogenicity of DXR. Instead, a statistically significant increase in the frequency of chromosomal damage was observed when the middle and the highest concentrations of curcumin were associated with DXR during the G1/S, S, and S/G2 phases of the cell cycle. The results clearly indicate the potentiating effect of curcumin on DXR-induced chromosomal damage.

Leptosins G, G1, G2 and H, belonging to a series of dimeric epipolythiodioxopiperazines, were isolated from the mycelium of a strain of Leptosphaeria sp. stuck on the marine alga Sargassum tortile. Their stereostructures were elucidated by chemical and spectral evidence.

Partition fractions of hexane, CCl4 and CHCl3 from methanolic extracts of marine algae were each examined for cytotoxic activities against cultured P-388 lymphocytic leukemia cells. Cytotoxic activities were found for partition fractions of 21 species of seaweed. Bioactivity-guided fractionation of the CCl4 partition fraction from Sargassum tortile, exhibiting the most prominent activity, afforded dihydroxysargaquinone (1) and sargatriol (2) previously isolated from this alga. The former was evaluated as a cytotoxic principle, and the latter, showing moderate activity, was suggested to be an artifact derived from 1 during the isolation procedure.

Cancer cells show characteristic gene expression profiles. Recent studies support the potential importance of microRNA (miRNA) expression signatures as biomarkers and therapeutic targets. The membrane-anchored protease regulator RECK is downregulated in many cancers, and forced expression of RECK in tumor cells results in decreased malignancy in animal models. RECK is also essential for mammalian development. In this study, we found that RECK is a target of at least three groups of miRNAs (miR-15b/16, miR-21 and miR-372/373); that RECK mutants lacking the target sites for these miRNA show augmented tumor/metastasis-suppressor activities; and that miR-372/373 are upregulated in response to hypoxia through HIF1α and TWIST1, whereas miR-21 is upregulated by RAS/ERK signaling. These data indicate that the hypoxia- and RAS-signaling pathways converge on RECK through miRNAs, cooperatively downregulating this tumor suppressor and thereby promoting malignant cell behavior. [ABSTRACT FROM AUTHOR]