Successful second-line treatment with cabozantinib for hepatocellular carcinoma harboring cytoplasmic mesenchymal-epithelial transition factor amplification.

A 72-year-old man with metastatic hepatocellular carcinoma previously received first-line systemic therapy with atezolizumab plus bevacizumab. His disease was judged to be progressing 5 months after treatment initiation. Comprehensive genomic profiling revealed cytoplasmic mesenchymal-epithelial transition factor amplification. On the basis of an expert panel's recommendation, he received cabozantinib as second-line therapy. The tumors shrank markedly and continued to shrink 6 months after treatment. Comprehensive genomic profiling could provide useful information for selecting effective second-line treatments for patients with hepatocellular carcinoma after first-line immunotherapy.

Inhibition of EGFR and MEK surmounts entrectinib resistance in a brain metastasis model of NTRK1-rearranged tumor cells.

Tropomyosin receptor kinase (TRK) inhibitors have demonstrated histology-agnostic efficacy in patients with neurotrophic receptor tyrosine kinase (NTRK) gene fusion. Although responses to TRK inhibitors can be dramatic and durable, duration of response may eventually be limited by acquired resistance via several mechanisms, including resistance mutations such as NTRK1-G595R. Repotrectinib is a second-generation TRK inhibitor, which is active against NTRK1-G595R. However, its efficacy against entrectinib-resistant tumors has not been fully elucidated. In the present study, we established entrectinib-resistant tumor cells (M3B) in a brain metastasis model inoculated with NTRK1-rearranged KM12SM cells and examined the sensitivity of M3B cells to repotrectinib. While M3B cells harbored the NTRK1-G595R mutation, they were unexpectedly resistant to repotrectinib. The resistance was due to extracellular signal-regulated kinase (ERK) reactivation partially mediated by epidermal growth factor receptor (EGFR) activation. We further demonstrate that the triplet combination of repotrectinib, EGFR inhibitor, and MEK inhibitor could sensitize M3B cells in vitro as well as in a brain metastasis model. These results indicate that resistant mutations, such as NTRK1-G595R, and alternative pathway activation, such as ERK activation, could simultaneously occur in entrectinib-resistant tumors, thereby causing resistance to second-generation inhibitor repotrectinib. These findings highlight the importance of intensive examinations to identify resistance mechanisms and application of the appropriate combination treatment to circumvent the resistance.

Trametinib overcomes KRAS-G12V-induced osimertinib resistance in a leptomeningeal carcinomatosis model of EGFR-mutant lung cancer.

Leptomeningeal carcinomatosis (LMC) occurs frequently in non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor (EGFR) mutations and is associated with acquired resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs). However, the mechanism by which LMC acquires resistance to osimertinib, a third-generation EGFR-TKI, is unclear. In this study, we elucidated the resistance mechanism and searched for a novel therapeutic strategy. We induced osimertinib resistance in a mouse model of LMC using an EGFR-mutant NSCLC cell line (PC9) via continuous oral osimertinib treatment and administration of established resistant cells and examined the resistance mechanism using next-generation sequencing. We detected the Kirsten rat sarcoma (KRAS)-G12V mutation in resistant cells, which retained the EGFR exon 19 deletion. Experiments involving KRAS knockdown in resistant cells and KRAS-G12V overexpression in parental cells revealed the involvement of KRAS-G12V in osimertinib resistance. Cotreatment with trametinib (a MEK inhibitor) and osimertinib resensitized the cells to osimertinib. Furthermore, in the mouse model of LMC with resistant cells, combined osimertinib and trametinib treatment successfully controlled LMC progression. These findings suggest a potential novel therapy against KRAS-G12V-harboring osimertinib-resistant LMC in EGFR-mutant NSCLC.

Multi-institutional survey of cancer disparities in disabled patients in the region of northwestern Japan.

BACKGROUND: Potential disparities between cancer patients with and without disabilities remained to be validate in Japan. METHODS: We surveyed retrospective data on hospital cancer registration as well as information on disability certificates obtained through the Hokushin Ganpro database. In total, 93,545 cancer patients in 10 principal hospitals covering the region of northwestern Japan were registered with the Hokushin Ganpro database between 2010 and 2015. The database included the following data: diagnosis date, cancer type, staging, treatment, cancer detection process, and possession of a disability certificate. RESULTS: We found that 2983 patients, which accounted for 3.2% of the total patients, had disabilities. No significant differences in gender, age at diagnosis, cancer stage distribution, and cancer incidence rates were observed between the disabled and non-disabled patients. Even though the proportion of early-stage cancer among disabled patients differed only slightly from that in non-disabled patients, early-stage cancer was more frequently diagnosed in patients with disabilities during their regular hospital visits than in those without disabilities, who had more opportunity for early cancer detection during cancer screening. According to in-house data reflecting treatment period and process from a single hospital, all 16 disabled patients treated with chemotherapy completed the treatment until disease progression or end of predetermined cycles. CONCLUSION: These results indicate that deep disparities between cancer patients with and without disabilities are not apparent and that the disabled patients in the region of northwestern Japan receive appropriate hospital follow-up.

Glycogen synthase kinase-3 inhibition overcomes epithelial-mesenchymal transition-associated resistance to osimertinib in EGFR-mutant lung cancer.

A novel epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor, osimertinib, has marked efficacy in patients with EGFR-mutant lung cancer. While epithelial-mesenchymal transition (EMT) plays a role in the resistance to various targeted drugs, its involvement in EGFR-inhibitor resistance remains largely unknown. Preclinical experiments with osimertinib-resistant lung cancer cells showed that EMT was associated with decreased microRNA-200c and increased ZEB1 expression. In several resistant clone cells, pretreatment with the histone deacetylase inhibitor quisinostat helped overcome the resistance by reverting EMT. Furthermore, drug screening from a library of 100 kinase inhibitors indicated that Glycogen synthase kinase-3 (GSK-3) inhibitors, such as LY2090314, markedly inhibited the growth and induced apoptosis of resistant cells, specifically those with a mesenchymal phenotype. These results suggest that GSK-3 inhibition could be useful to circumvent EMT-associated resistance to osimertinib in EGFR-mutant lung cancer.

MET amplification results in heterogeneous responses to osimertinib in EGFR-mutant lung cancer treated with erlotinib.

The third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) osimertinib is approved for untreated, or previously EGFR-TKI-treated T790M-positive EGFR-mutated non-small cell lung carcinoma (NSCLC). We investigated the heterogeneity of responses to osimertinib and its underlying mechanisms. A patient with EGFR-L858R-mutated NSCLC was treated with erlotinib. Following treatment, he developed brain and multiple bone metastases and was eventually diagnosed with NSCLC with EGFR-T790M mutation. The responses of various tumor specimens to osimertinib were heterogeneous. We investigated EGFR-T790M and MET amplification using PCR and FISH in autopsy specimens of the cervical spine, lumbar spine, and brain. We established the KNZ osimertinib-resistant (KNZ_OR) tumor cell line with MET amplification using a cervical spine lesion that was intrinsically resistant to osimertinib. We evaluated the effects of MET knockdown and MET inhibitor on KNZ_OR cell sensitivity to osimertinib in vitro and in vivo. Osimertinib-resistant lesions (cervical spine and brain) showed EGFR-L858R and MET amplification, but not EGFR-T790M, whereas osimertinib-sensitive lesions (lumbar spine) showed EGFR-L858R and -T790, but not MET amplification. Osimertinib decreased the association of amplified MET with L858R-mutated EGFR but increased that with human epidermal growth factor receptor 3 in KNZ_OR cells. MET knockdown or MET inhibitor sensitized KNZ_OR cells to osimertinib in vitro, indicating that MET amplification induced osimertinib resistance. Combination with osimertinib plus crizotinib induced tumor shrinkage in the KNZ_OR xenograft model. Hence, MET amplification might induce heterogeneous responses to osimertinib in EGFR-mutated NSCLC. Further investigations on mutated EGFR and amplified MET might lead to the development of effective therapies.

Phase I study of vorinostat with gefitinib in BIM deletion polymorphism/epidermal growth factor receptor mutation double-positive lung cancer.

Patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC) harboring BIM deletion polymorphism (BIM deletion) have poor responses to EGFR TKI. Mechanistically, the BIM deletion induces preferential splicing of the non-functional exon 3-containing isoform over the functional exon 4-containing isoform, impairing TKI-induced, BIM-dependent apoptosis. Histone deacetylase inhibitor, vorinostat, resensitizes BIM deletion-containing NSCLC cells to EGFR-TKI. In the present study, we determined the safety of vorinostat-gefitinib combination and evaluated pharmacodynamic biomarkers of vorinostat activity. Patients with EGFR-mutated NSCLC with the BIM deletion, pretreated with EGFR-TKI and chemotherapy, were recruited. Vorinostat (200, 300, 400 mg) was given daily on days 1-7, and gefitinib 250 mg was given daily on days 1-14. Vorinostat doses were escalated based on a conventional 3 + 3 design. Pharmacodynamic markers were measured using PBMC collected at baseline and 4 hours after vorinostat dose on day 2 in cycle 1. No dose-limiting toxicities (DLT) were observed in 12 patients. We determined 400 mg vorinostat as the recommended phase II dose (RP2D). Median progression-free survival was 5.2 months (95% CI: 1.4-15.7). Disease control rate at 6 weeks was 83.3% (10/12). Vorinostat preferentially induced BIM mRNA-containing exon 4 over mRNA-containing exon 3, acetylated histone H3 protein, and proapoptotic BIMEL protein in 11/11, 10/11, and 5/11 patients, respectively. These data indicate that RP2D was 400 mg vorinostat combined with gefitinib in BIM deletion/EGFR mutation double-positive NSCLC. BIM mRNA exon 3/exon 4 ratio in PBMC may be a useful pharmacodynamic marker for treatment.

Reduced doses of dabrafenib and trametinib combination therapy for BRAF V600E-mutant non-small cell lung cancer prevent rhabdomyolysis and maintain tumor shrinkage: a case report.

BACKGROUND: A BRAF V600E mutation is found as driver oncogene in patients with non-small cell lung cancer. Although combined treatment with dabrafenib and trametinib is highly effective, the efficacy of reduced doses of the drugs in combination therapy has not yet been reported. CASE PRESENTATION: A Japanese man in his mid-sixties was diagnosed with unresectable lung adenocarcinoma and was unresponsive to cytotoxic chemotherapy and immune checkpoint inhibitors. The BRAF V600E mutation was detected by next generation sequencing, and the patient was subjected to treatment with dabrafenib and trametinib in combination. Although the treatment reduced the tumor size, he experienced myalgia and muscle weakness with elevated serum creatine kinase and was diagnosed with rhabdomyolysis induced by dabrafenib and trametinib. After the patient recovered from rhabdomyolysis, the treatment doses of dabrafenib and trametinib were reduced, which prevented further rhabdomyolysis and maintained tumor shrinkage. CONCLUSION: The reduction of the doses of dabrafenib and trametinib was effective in the treatment of BRAF V600E-mutant NSCLC, and also prevented the incidence of rhabdomyolysis.

Patient-derived xenograft models of non-small cell lung cancer for evaluating targeted drug sensitivity and resistance.

Patient-derived xenograft (PDX) models are a useful tool in cancer biology research. However, the number of lung cancer PDX is limited. In the present study, we successfully established 10 PDX, including three adenocarcinoma (AD), six squamous cell carcinoma (SQ) and one large cell carcinoma (LA), from 30 patients with non-small cell lung cancer (NSCLC) (18 AD, 10 SQ, and 2 LA), mainly in SCID hairless outbred (SHO) mice (Crlj:SHO-Prkdcscid Hrhr ). Histology of SQ, advanced clinical stage (III-IV), status of lymph node metastasis (N2-3), and maximum standardized uptake value ≥10 when evaluated using a delayed 18 F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) scan was associated with successful PDX establishment. Histological analyses showed that PDX had histology similar to that of patients' surgically resected tumors (SRT), whereas components of the microenvironment were replaced with murine cells after several passages. Next-generation sequencing analyses showed that after two to six passages, PDX preserved the majority of the somatic mutations and mRNA expressions of the corresponding SRT. Two out of three PDX with AD histology had epidermal growth factor receptor (EGFR) mutations (L858R or exon 19 deletion) and were sensitive to EGFR tyrosine kinase inhibitors (EGFR-TKI), such as gefitinib and osimertinib. Furthermore, in one of the two PDX with an EGFR mutation, osimertinib resistance was induced that was associated with epithelial-to-mesenchymal transition. This study presented 10 serially transplantable PDX of NSCLC in SHO mice and showed the use of PDX with an EGFR mutation for analyses of EGFR-TKI resistance.

[Qualitative Real-Time PCR Method for Poisonous Entoloma rhodopolium-Related Species in Japan: Real-Time PCR Method for Entoloma Mushrooms].

Qualitative real-time PCR method for three poisonous Entoloma rhodopolium-related species in Japan was established using specific primers and FAM, VIC, Texas Red, Cy5-labeled probes. The use of multicolor probes can extend the method to simultaneous detection of different targets. Standard plasmids were constructed as reference materials. Designed primers and probes in the method detect only a target species, and the detection limit was 12.5 copies or below. This indicates it is highly specific and sensitive enough to detect the poisonous mushrooms in food residues. Next, we applied the method to four food residue samples obtained from food poisoning cases. The real-time PCR method did identify all of four samples as E. subrhodopolium and E. pseudorhodopolium, whereas PCR-RFLP did not. The method established here revealed Entoloma rhodopolium-related species in Hokkaido were different species such as E. eminens and unknown species.

Pulmonary carcinosarcoma showing an obvious response to pazopanib: a case report.

BACKGROUND: Pulmonary carcinosarcoma (PCS) is a rare primary lung malignancy and has a poor prognosis among lung tumor histological subtypes. However, an appropriate treatment strategy has not been developed for unresectable PCS. CASE PRESENTATION: A 65-year-old man who was diagnosed with PCS was treated by surgical removal of the primary lung lesion, followed by six cycles of adjuvant chemotherapy with cisplatin plus irinotecan. Following the chemotherapy, he experienced a relapse with brain metastasis, which induced the rapid onset of left leg paralysis. Radical surgical resection and stereotactic radiosurgery to the resection cavity were performed. However, meningeal dissemination and new lung metastases occurred after a year and half. To control these multiple metastatic lesions, the patient was treated with the multiple kinase inhibitor pazopanib. No change was observed in the meningeal dissemination, while the metastatic lung lesions were prominently reduced in size following treatment with pazopanib. Consequently, the patient showed a partial response to pazopanib treatment, although the dose of pazopanib was reduced by half as a result of thrombocytopenia. CONCLUSION: This is the first report of metastatic PCS showing an evident therapeutic response to tumor-targeted therapy. We suggest that pazopanib may be a therapeutic option for patients with metastatic PCS.

Impact of MET inhibition on small-cell lung cancer cells showing aberrant activation of the hepatocyte growth factor/MET pathway.

Small-cell lung cancer (SCLC) accounts for approximately 15% of all lung cancers, and is characterized as extremely aggressive, often displaying rapid tumor growth and multiple organ metastases. In addition, the clinical outcome of SCLC patients is poor due to early relapse and acquired resistance to standard chemotherapy treatments. Hence, novel therapeutic strategies for the treatment of SCLC are urgently required. Accordingly, several molecular targeted therapies were evaluated in SCLC; however, they failed to improve the clinical outcome. The receptor tyrosine kinase MET is a receptor for hepatocyte growth factor (HGF), and aberrant activation of HGF/MET signaling is known as one of the crucial mechanisms enabling cancer progression and invasion. Here, we found that the HGF/MET signaling was aberrantly activated in chemoresistant or chemorelapsed SCLC cell lines (SBC-5, DMS273, and DMS273-G3H) by the secretion of HGF and/or MET copy number gain. A cell-based in vitro assay revealed that HGF/MET inhibition, induced either by MET inhibitors (crizotinib and golvatinib), or by siRNA-mediated knockdown of HGF or MET, constrained growth of chemoresistant SCLC cells through the inhibition of ERK and AKT signals. Furthermore, treatment with either crizotinib or golvatinib suppressed the systemic metastasis of SBC-5 cell tumors in natural killer cell-depleted SCID mice, predominantly through cell cycle arrest. These findings reveal the therapeutic potential of targeting the HGF/MET pathway for inhibition, to constrain tumor progression of SCLC cells showing aberrant activation of HGF/MET signaling. We suggest that it would be clinically valuable to further investigate HGF/MET-mediated signaling in SCLC cells.

Amphiregulin triggered epidermal growth factor receptor activation confers in vivo crizotinib-resistance of EML4-ALK lung cancer and circumvention by epidermal growth factor receptor inhibitors.

Crizotinib, a first-generation anaplastic lymphoma kinase (ALK) tyrosine-kinase inhibitor, is known to be effective against echinoderm microtubule-associated protein-like 4 (EML4)-ALK-positive non-small cell lung cancers. Nonetheless, the tumors subsequently become resistant to crizotinib and recur in almost every case. The mechanism of the acquired resistance needs to be deciphered. In this study, we established crizotinib-resistant cells (A925LPE3-CR) via long-term administration of crizotinib to a mouse model of pleural carcinomatous effusions; this model involved implantation of the A925LPE3 cell line, which harbors the EML4-ALK gene rearrangement. The resistant cells did not have the secondary ALK mutations frequently occurring in crizotinib-resistant cells, and these cells were cross-resistant to alectinib and ceritinib as well. In cell clone #2, which is one of the clones of A925LPE3-CR, crizotinib sensitivity was restored via the inhibition of epidermal growth factor receptor (EGFR) by means of an EGFR tyrosine-kinase inhibitor (erlotinib) or an anti-EGFR antibody (cetuximab) in vitro and in the murine xenograft model. Cell clone #2 did not have an EGFR mutation, but the expression of amphiregulin (AREG), one of EGFR ligands, was significantly increased. A knockdown of AREG with small interfering RNAs restored the sensitivity to crizotinib. These data suggest that overexpression of EGFR ligands such as AREG can cause resistance to crizotinib, and that inhibition of EGFR signaling may be a promising strategy to overcome crizotinib resistance in EML4-ALK lung cancer.

Podoplanin promotes progression of malignant pleural mesothelioma by regulating motility and focus formation.

Malignant pleural mesothelioma (MPM) is characterized by dissemination and aggressive growth in the thoracic cavity. Podoplanin (PDPN) is an established diagnostic marker for MPM, but the function of PDPN in MPM is not fully understood. The purpose of this study was to determine the pathogenetic function of PDPN in MPM. Forty-seven of 52 tumors (90%) from Japanese patients with MPM and 3/6 (50%) MPM cell lines tested positive for PDPN. Knocking down PDPN in PDPN-high expressing MPM cells resulted in decreased cell motility. In contrast, overexpression of PDPN in PDPN-low expressing MPM cells enhanced cell motility. PDPN stimulated motility was mediated by activation of the RhoA/ROCK pathway. Moreover, knocking down PDPN with short hairpin (sh) RNA in PDPN-high expressing MPM cells resulted in decreased development of a thoracic tumor in mice with severe combined immune deficiency (SCID). In sharp contrast, transfection of PDPN in PDPN-low expressing MPM cells resulted in an increase in the number of Ki-67-positive proliferating tumor cells and it promoted progression of a thoracic tumor in SCID mice. Interestingly, PDPN promoted focus formation in vitro, and a low level of E-cadherin expression and YAP1 activation was observed in PDPN-high MPM tumors. These findings indicate that PDPN is a diagnostic marker as well as a pathogenetic regulator that promotes MPM progression by increasing cell motility and inducing focus formation. Therefore, PDPN might be a pathogenetic determinant of MPM dissemination and aggressive growth and may thus be an ideal therapeutic target.

Biochanin A enhances RORγ activity through STAT3-mediated recruitment of NCOA1.

Interleukin (IL)-17-producing T cells play important roles in autoimmunity, chronic inflammation and host protection against extracellular bacteria and fungi. The retinoic acid receptor-related orphan receptors (ROR) α and γ are key regulators of the IL-17-producing phenotype. We previously showed that the isoflavone biochanin A enhanced ROR-mediated transcriptional activity. Here, we investigated the possible mechanisms underlying this ROR activation. Biochanin A-treated murine thymoma EL4 and primary splenocytes demonstrated enhanced induction of IL-17. Biochanin A also induced tyrosine-phosphorylation of signal transducer and activator of transcription 3 (STAT3) in these cells. Stable knockdown of either RORγ or STAT3 in EL4 cells canceled biochanin A-induced upregulation of IL-17 expression. Importantly, biochanin A enhanced complex formation between RORγ and STAT3 or nuclear-receptor coactivator 1 (NCOA1). Furthermore, the biochanin A-induced RORγ-NCOA1 complex was disrupted by a dominant negative mutant of STAT3 or by the STAT3 specific inhibitor Stattic. These results suggest that biochanin A activates RORγ-dependent IL-17 transcription through the enhancement of STAT3 phosphorylation and STAT3-mediated recruitment of NCOA1 to RORγ.

Organ-specific efficacy of HSP90 inhibitor in multiple-organ metastasis model of chemorefractory small cell lung cancer.

Small-cell lung cancer (SCLC) accounts for nearly 15% of lung cancer cases and exhibits aggressive clinical behavior characterized by rapid growth and metastatic spread to multiple organs. About 70% of patients with SCLC present with extensive disease and distant metastases at diagnosis. HSP90 is a 90-kDa molecular chaperone whose association is required for the stability and function of its numerous "client proteins." Here, we assessed the therapeutic potential of the HSP90 inhibitor 17-DMAG in SCLC. Notably, 17-DMAG hindered the viability of human SCLC cell lines-regardless of their chemosensitivity-via the decreased expression of client proteins, including the proto-oncogene c-Raf (also known as RAF1). In an in vivo imaging model of SCLC multiple-organ metastasis with the human SCLC cell line SBC-5, treatment with 17-DMAG remarkably inhibited the formation of metastatic sites in the liver, but was ineffective in hindering the progression of bone lesions. The latter was likely the result of activation of osteoclasts. IGF-1, which is supposed to be rich in bone environment, preserved c-Raf expression and maintained viability of SBC-5 cells treated with 17-DMAG. Furthermore, the combined use of a bisphosphonate with 17-DMAG significantly attenuated the progression of metastases in both the liver and the bone. These findings suggest that therapeutic effects of HSP90 inhibitors may be organ-specific and should be carefully monitored in SCLC clinical trials.

In vivo imaging models of bone and brain metastases and pleural carcinomatosis with a novel human EML4-ALK lung cancer cell line.

EML4-ALK lung cancer accounts for approximately 3-7% of non-small-cell lung cancer cases. To investigate the molecular mechanism underlying tumor progression and targeted drug sensitivity/resistance in EML4-ALK lung cancer, clinically relevant animal models are indispensable. In this study, we found that the lung adenocarcinoma cell line A925L expresses an EML4-ALK gene fusion (variant 5a, E2:A20) and is sensitive to the ALK inhibitors crizotinib and alectinib. We further established highly tumorigenic A925LPE3 cells, which also have the EML4-ALK gene fusion (variant 5a) and are sensitive to ALK inhibitors. By using A925LPE3 cells with luciferase gene transfection, we established in vivo imaging models for pleural carcinomatosis, bone metastasis, and brain metastasis, all of which are significant clinical concerns of advanced EML4-ALK lung cancer. Interestingly, crizotinib caused tumors to shrink in the pleural carcinomatosis model, but not in bone and brain metastasis models, whereas alectinib showed remarkable efficacy in all three models, indicative of the clinical efficacy of these ALK inhibitors. Our in vivo imaging models of multiple organ sites may provide useful resources to analyze further the pathogenesis of EML4-ALK lung cancer and its response and resistance to ALK inhibitors in various organ microenvironments.

Metabolism of UV-filter benzophenone-3 by rat and human liver microsomes and its effect on endocrine-disrupting activity.

Benzophenone-3 (2-hydroxy-4-methoxybenzophenone; BP-3) is widely used as sunscreen for protection of human skin and hair from damage by ultraviolet (UV) radiation. In this study, we examined the metabolism of BP-3 by rat and human liver microsomes, and the estrogenic and anti-androgenic activities of the metabolites. When BP-3 was incubated with rat liver microsomes in the presence of NADPH, 2,4,5-trihydroxybenzophenone (2,4,5-triOH BP) and 3-hydroxylated BP-3 (3-OH BP-3) were newly identified as metabolites, together with previously detected metabolites 5-hydroxylated BP-3 (5-OH BP-3), a 4-desmethylated metabolite (2,4-diOH BP) and 2,3,4-trihydroxybenzophenone (2,3,4-triOH BP). In studies with recombinant rat cytochrome P450, 3-OH BP-3 and 2,4,5-triOH BP were mainly formed by CYP1A1. BP-3 was also metabolized by human liver microsomes and CYP isoforms. In estrogen reporter (ER) assays using estrogen-responsive CHO cells, 2,4-diOH BP exhibited stronger estrogenic activity, 2,3,4-triOH BP exhibited similar activity, and 5-OH BP-3, 2,4,5-triOH BP and 3-OH BP-3 showed lower activity as compared to BP-3. Structural requirements for activity were investigated in a series of 14 BP-3 derivatives. When BP-3 was incubated with liver microsomes from untreated rats or phenobarbital-, 3-methylcholanthrene-, or acetone-treated rats in the presence of NADPH, estrogenic activity was increased. However, liver microsomes from dexamethasone-treated rats showed decreased estrogenic activity due to formation of inactive 5-OH BP-3 and reduced formation of active 2,4-diOH BP. Anti-androgenic activity of BP-3 was decreased after incubation with liver microsomes.

Case report: Navigating treatment pathways for cardiac intimal sarcoma with PDGFRß N666K mutation.

In the realm of rare cardiac tumors, intimal sarcoma presents a formidable challenge, often requiring innovative treatment approaches. This case report presents a unique instance of primary intimal sarcoma in the left atrium, underscoring the critical role of genomic profiling in guiding treatment. Initial genomic testing unveiled a somatic, active mutation in PDGFRß (PDGFRß N666K), accompanied by MDM2 and CDK4 amplifications. This discovery directed the treatment course toward pazopanib, a PDGFRß inhibitor, following irradiation. The patient's response was remarkable, with the therapeutic efficacy of pazopanib lasting for 16.3 months. However, the patient experienced a recurrence in the left atrium, where subsequent genomic analysis revealed the absence of the PDGFRß N666K mutation and a significant reduction in PDGFRß expression. This case report illustrates the complexities and evolving nature of cardiac intimal sarcoma treatment, emphasizing the potential of PDGFRß signaling as a strategic target and highlighting the importance of adapting treatment pathways in response to genetic shifts.

Targeting WEE1 enhances the antitumor effect of KRAS-mutated non-small cell lung cancer harboring TP53 mutations.

The clinical development of Kirsten rat sarcoma virus (KRAS)-G12C inhibitors for the treatment of KRAS-mutant lung cancer is limited by the presence of co-mutations, intrinsic resistance, and the emergence of acquired resistance. Therefore, innovative strategies for enhancing apoptosis in KRAS-mutated non-small cell lung cancer (NSCLC) are urgently needed. Through CRISPR-Cas9 knockout screening using a library of 746 crRNAs and drug screening with a custom library of 432 compounds, we discover that WEE1 kinase inhibitors are potent enhancers of apoptosis, particularly in KRAS-mutant NSCLC cells harboring TP53 mutations. Mechanistically, WEE1 inhibition promotes G2/M transition and reduces checkpoint kinase 2 (CHK2) and Rad51 expression in the DNA damage response (DDR) pathway, which is associated with apoptosis and the repair of DNA double-strand breaks, leading to mitotic catastrophe. Notably, the combined inhibition of KRAS-G12C and WEE1 consistently suppresses tumor growth. Our results suggest targeting WEE1 as a promising therapeutic strategy for KRAS-mutated NSCLC with TP53 mutations.