No abstract

A hallmark of aged mesenchymal stem/progenitor cells (MSCs) in bone marrow is the pivot of differentiation potency from osteoblast to adipocyte coupled with a decrease in self-renewal capacity. However, how these cellular events are orchestrated in the aging progress is not fully understood. In this study, we have used molecular and genetic approaches to investigate the role of forkhead box P1 (FOXP1) in transcriptional control of MSC senescence. In bone marrow MSCs, FOXP1 expression levels declined with age in an inverse manner with those of the senescence marker p16INK4A. Conditional depletion of Foxp1 in bone marrow MSCs led to premature aging characteristics, including increased bone marrow adiposity, decreased bone mass, and impaired MSC self-renewal capacity in mice. At the molecular level, FOXP1 regulated cell-fate choice of MSCs through interactions with the CEBPβ/δ complex and recombination signal binding protein for immunoglobulin κ J region (RBPjκ), key modulators of adipogenesis and osteogenesis, respectively. Loss of p16INK4A in Foxp1-deficient MSCs partially rescued the defects in replication capacity and bone mass accrual. Promoter occupancy analyses revealed that FOXP1 directly represses transcription of p16INK4A. These results indicate that FOXP1 attenuates MSC senescence by orchestrating their cell-fate switch while maintaining their replicative capacity in a dose- and age-dependent manner.

This study provides an assessment of tumor cMET gene copy number changes and protein overexpression incidence in a cohort of Chinese GC patients. To our knowledge, this is the first study to demonstrate anti-tumor efficacy in a panel of cMET-dysregulated gastric cancer PDX models, using a novel selective cMET-inhibitor (volitinib). Thus, the translational science presented here provides strong rationale for the investigation of volitinib as a therapeutic option for patients with GC tumors harboring amplified cMET.

HGF/c-Met signaling has been implicated in human cancers. Herein we describe the invention of a series of novel triazolopyrazine c-Met inhibitors. The structure-activity relationship of these compounds was investigated, leading to the identification of compound 28, which demonstrated favorable pharmacokinetic properties in mice and good antitumor activities in the human glioma xenograft model in athymic nude mice.

Osteosarcoma (OS) is one of the most common malignant bone tumors in early adolescence. Multi-drug chemotherapy has greatly increased the five year survival rate from 20% to 70%. However, the rate has been staggering for 30 years and the prognosis is particularly poor for patients with recurrence and metastasis. Our study aimed to investigate the role of Wnt-β-catenin, Notch and Hedgehog pathway in OS development because all these pathways are involved in skeletal development, tumorigenesis and chemoresistance. Our results showed that the major components in Wnt-β-catenin pathway, e.g. Wnt3a, β-catenin and Lef1, were consistently upregulated in human osteosarcoma cell line Saos2 cells compared to human fetal osteoblasts (hFOB), whereas the changes in the expression levels of Notch and Hh signaling molecules were not consistent. Knocking down β-catenin increased the Saos2 sensitivity to methotrexate (MTX) induced cell death. Consistently, the expression level of β-catenin protein correlated with the invasiveness of OS, as evidenced by more intensive β-catenin immunoreactivity in higher grade OS samples. Chemical inhibition of the Wnt-β-catenin signaling enhanced MTX mediated death of Saos2 cells. A synergistic effect with MTX was observed when both inhibitors for Wnt-β-catenin and Notch pathways were simultaneously used, while the addition of the Hh inhibitor did not further improve the efficacy. Our findings provide some novel insight to OS pathogenesis and lay a foundation for future application of Wnt-β-catenin and Notch inhibitors together with the currently used chemotherapeutic drugs to improve the outcome of OS treatment.

No abstract

Purpose: No antiangiogenic treatment is yet approved for extrapancreatic neuroendocrine tumors (NET). Surufatinib (HMPL-012, previously named sulfatinib) is a small-molecule inhibitor targeting vascular endothelial growth factor receptors, fibroblast growth factor receptor 1 and colony-stimulating factor 1 receptor. We conducted a single-arm phase Ib/II study of surufatinib in advanced NETs.Patients and Methods: Patients with histologically welldifferentiated, low or intermittent grade, inoperable or metastatic NETs were enrolled into a pancreatic or extrapancreatic NET cohort. Patients were treated with surufatinib 300 mg orally, once daily. The primary endpoints were safety and objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors (version 1.1).Results: Of the 81 patients enrolled, 42 had pancreatic NETs and 39 had extrapancreatic NETs. Most patients had radiologic progression within 1 year prior to enrollment (32 patients in each cohort). In the pancreatic and extrapancreatic NET cohorts, ORRs were 19% [95% confidence intervals (CI), 9-34] and 15% (95% CI, 6-31), disease control rates were 91% (95% CI, 77-97) and 92% (95% CI, 79-98), and median progression-free survival was 21.2 months (95% CI, 15.9-24.8) and 13.4 months (95% CI, 7.6-19.3), respectively. The most common grade !3 treatment-related adverse events were hypertension (33%), proteinuria (12%), hyperuricemia (10%), hypertriglyceridemia, and diarrhea (6% for each), and increased alanine aminotransferase (5%).Conclusions: Surufatinib showed encouraging antitumor activity and manageable toxicities in patients with advanced NETs. Two ongoing phase III studies, validating the efficacy of surufatinib in patients with NETs, will contribute to the clinical evidence.

9519 Background: There are unmet medical needs for pts with METex14+ NSCLC. PSC is a rare type of NSCLC with high incidence of MET exon 14 mutations and poor prognosis. Savolitinib (AZD6094, HMPL-504, volitinib) is a highly selective oral MET tyrosine kinase inhibitor, and its anti-tumor activity has been shown in combination with osimertinib in pts with EGFR-mutant, MET-amplified NSCLC (Yu H, et al. 2019 AACR, Abstract CT032). Methods: This was a multicenter, multi-cohort, single-arm phase II study (NCT02897479) to evaluate the efficacy, safety, and pharmacokinetics of savolitinib in pts with unresectable or metastatic METex14+ PSC and other NSCLC. MET mutation was tested or retrospectively confirmed by central laboratory. Savolitinib was taken orally, once daily (QD) (600mg for weight ≥50kg or 400mg weight < 50kg) until disease progression or intolerable toxicity. Tumor was evaluated every 6 weeks during the 1st year and every 12 weeks thereafter. The primary endpoint was independent review committee (IRC) assessed objective response rate (ORR) (RECIST version 1.1). Here we report the results of one cohort of prior MET-treatment naïve patients. Results: As of October 31, 2019, 593 pts were pre-screened/screened, 87 identified with METex14+ and 70 treated. Among treated pts, median age was 68.7 years (range 51.7-85.0), 58.6% pts were male, 92.9% stage IV, 60.0% previously treated, 57.1% with adenocarcinoma, 35.7% with PSC and the rest with other pathological types. Sixty-one pts were efficacy evaluable by IRC assessment (N = 61) (including pts who had at least one measurable lesion at baseline and had ≥1 scheduled post-baseline tumor assessment or evidence of any post-baseline radiological disease progression): ORR was 47.5% (95% CI: 34.6%, 60.7%), disease control rate 93.4% (95% CI: 84.1%, 98.2%) and median duration of response not reached yet. The median progression-free survival was 6.8 months (95% CI 4.2, 13.8) among all treated pts. Efficacy results were consistent with investigators’assessments. The most common (≥20%) treatment-related adverse events (TRAEs) were peripheral edema, nausea, increased AST/ALT, vomiting and hypoalbuminemia. The incidence of ≥ grade 3 TRAEs was 41.4%. TRAEs leading to treatment discontinuation occurred in 14.3% pts, among which liver injury and hypersensitivity were most common (each 2.9%). Conclusions: Savolitinib demonstrated promising anti-tumor activity and acceptable tolerability in METex14+ NSCLC pts. Clinical trial information: NCT02897479 .