1stOncology™: Cancer Intelligence Service – Page 15696 – 1stOncology is recognized as a Top 10 Global Pharma Analytic Provider

Transcription Blockage Leads to New Beginnings.

Environmental agents are constantly challenging cells by damaging DNA, leading to the blockage of transcription elongation. How do cells deal with transcription-blockage and how is transcription restarted after the blocking lesions are removed? Here we review the processes responsible for the removal of transcription-blocking lesions, as well as mechanisms of transcription restart. We also discuss recent data suggesting that blocked RNA polymerases may not resume transcription from the site of the lesion following its removal but, rather, are forced to start over from the beginning of genes.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

Schedule Your 30 min Free Demo!

Outcome of uterine sarcoma patients treated with pazopanib: A retrospective analysis based on two European Organisation for Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group (STBSG) clinical trials 62043 and 62072.

Uterine sarcomas are a group of mesenchymal tumours comprising several histologies. They have a high recurrence rate following surgery, modest outcome to systemic therapy, and poor overall survival. Pazopanib is a multi-targeted tyrosine kinase inhibitor approved for non-adipocytic advanced soft tissue sarcomas (STS). Here we investigated whether response to pazopanib in patients with uterine sarcomas differs from that of patients with non-uterine sarcomas.
Uterine sarcoma patients were retrieved from all soft tissue sarcoma patients treated with pazopanib in EORTC Phase II (n=10) and Phase III (PALETTE) (n=34) studies. Patient and tumour characteristics, response, progression free and overall survival data were compared.
Forty-four patients with uterine sarcoma were treated with pazopanib. The majority of patients had uterine leiomyosarcoma (LMS) (n=39, 88.6%) with high grade tumours (n=37, 84.1%) compared to 54.8% (n=164) in the non-uterine population. The median age was 55years (range 33-79) and median follow up was 2.3years. Uterine patients were heavily pre-treated, 61.3% having ≥2 lines of chemotherapy prior to pazopanib compared to 40.8% in the non-uterine population. Five patients (11%), all LMS, had a partial response (95% CI 3.8-24.6). Median progression free survival (PFS) 3.0months (95% CI 2.5-4.7) in uterine versus 4.5 (95% CI 3.7-5.1) in non-uterine STS. Median overall survival (OS) was 17.5months (95% CI 11.1-19.6), longer than the non-uterine population, 11.1months (95% CI 10.2-12.0) (p=0.352).
Despite heavy pre-treatment, pazopanib shows signs of activity in patients with uterine sarcoma with the similar outcomes to patients with non-uterine STS.
Copyright © 2015. Published by Elsevier Inc.

Assessing the Effects of Concurrent versus Sequential Cisplatin/Radiotherapy on Immune Status in Lung Tumor-Bearing C57BL/6 Mice.

Concurrent and sequential cisplatin-based chemoradiotherapy regimens are standard therapeutic approaches in cancer treatment. Recent clinical data suggest that these different dosing schedules may adversely affect antigen-specific immunotherapy. The goal of the present preclinical study was to explore the effects of concurrent and sequential cisplatin/radiotherapy on immune status in a lung cancer mouse model. A total of 150 C57BL/6 mice were randomized into six treatment groups: control; 8 Gy thoracic radiotherapy (dose schedules 1 and 2); cisplatin 2.5 mg/kg i.p.; cisplatin + radiotherapy (concurrent); and cisplatin + radiotherapy (sequential; n = 25, all groups). At the end of the study (week 41), serum cytokines were assessed by multiplex immunoassay, surface markers of spleen-derived lymphocytes were assessed by immunostaining and flow cytometry, lung tumor expression of programmed death ligands 1 and 2 (PD-L1/2) was evaluated by immunohistochemistry, and miRNA profiling was performed in serum and lymphocytes by quantitative real-time PCR. Lung whole mounts were prepared to assess treatment effects on lung tumor foci formation. The results showed that sequential chemoradiotherapy (two cycles of cisplatin followed by 8 Gy radiotherapy) had equivalent antitumor activity as concurrent therapy. However, sequential cisplatin/radiotherapy resulted in significant differences in several immune response biomarkers, including regulatory T cells, miR-29c, expression of costimulatory molecule CD28, and serum IFNγ. PD-L1 and PD-L2 were strongly expressed in tumor foci, but no trend was seen between groups. These results suggest that monitoring immune status may be necessary when designing treatment regimens combining immunotherapy with chemoradiotherapy.
©2015 American Association for Cancer Research (AACR) (Free AACR Whitepaper).

Surface-based chondroblastoma of the tibia: a unique presentation.

Chondroblastoma is a benign tumor classically located within the epiphysis of the long bones. The tumor is believed to arise from immature cells of the epiphyseal plate. Purely metaphyseal or diaphyseal chondroblastoma is exceedingly uncommon, occurring in approximately 2% of chondroblastoma cases. In all of these non-epiphyseal-based cases, the tumor has been intramedullary.
We describe the histologic and imaging features of the first detailed description of a surface-based chondroblastoma.
The tumor was located in the anteromedial midshaft of the tibia in a 47-year-old male.
We discuss the diagnostic considerations and possible etiology of chondroblastoma given this unusual location.

Oral proteasome inhibitor with strong preclinical efficacy in myeloma models.

The proteasome is a validated anti-cancer target and various small-molecule inhibitors are currently in clinical development or on the market. However, adverse events and resistance associated with those proteasome inhibitors indicate the need for a new generation of drugs. Therefore, we focused on developing an oral proteasome inhibitor with improved efficacy and safety profiles.
The in vitro inhibition of the 20S proteasome catalytic activities was determined in human multiple myeloma (MM) cellular lysates with fluorogenic peptide substrates specific for each catalytic subunit. Cell cytotoxicity was assessed with the ATP bioluminescence assay using human cell samples from tumor cell lines, MM patients or normal healthy donors. In mice bearing human MM xenografts, a single dose of LC53-0110 was administered orally, and concentration-time profiles of LC53-0110 and the 20S proteasome catalytic activities in plasma, blood, and tumor were determined. The efficacy of repeat-dose compound with regard to tumor growth inhibition in vivo was also evaluated in the same MM xenograft models.
LC53-0110 is far more specific for the chymotrypsin-like proteolytic (β5) site of the 20S proteasome as compared to bortezomib, carfilzomib, or ixazomib. LC53-0110 treatment showed accumulation of ubiquitinated proteins, inhibited cell viability with a low nM range potency in various tumor cell lines, and showed potent activity on CD138(+) cells isolated from MM patients who are resistant/refractory to current FDA-approved drug treatment. When a single dose was administered orally to tumor-bearing mice, LC53-0110 showed both greater maximum and sustained tumor proteasome inhibition as compared with ixazomib in MM xenograft models. The robust pharmacodynamic responses in tumor correlated with tumor growth regression. In addition, LC53-0151, an analog of LC53-0110, in combination with pomalidomide, a third-generation immunomodulatory drug, showed synergistic inhibition of tumor growth both in vitro and in the xenograft mouse model.
In view of the in vitro, in vivo, and ex vivo profiles, further investigation of additional LC compounds in preclinical studies is warranted for the nomination of a clinical development candidate.