First International Workshopson Provocative Questions (PQ) in Cancer Research, October-November 2014, New Delhi, Bengaluru, and Thiruvananthapuram, India.

In 2011, the National Cancer Institute (NCI, USA) introduced the Provocative Questions (PQ) Initiative, a new approach allowing active researchers to define major unsolved or neglected problems in oncology unaddressed by existing funding. Last year, the U.S. NCI teamed up with the Indian Department of Biotechnology (DBT) to pilot the PQ approach in three cities in India. Workshop outcomes includedthe generation of fundable "PQs" (perplexing questions understudied by the international scientific community), as well as the identification of several non-PQ projects and research-related issues of importance to DBT and other Indian funding groups. The workshops clearly indicated the need to expand beyond crafting "PQs" when considering the best areas for research funding in international settings. Nonetheless, the first set of PQ workshops provided a forum to discuss key issues regarding cancer research in India, including the paucity of cancer research funding, and the lack of relevant human resource training and technology sharing platforms. Continued open debate between researchers, funders and policymakers will be essential to effectively strengthen the cancer research portfolio in India.

Identification of small molecule inhibitors of pyruvate kinase M2.

A common feature of tumors arising from diverse tissue types is a reliance on aerobic glycolysis for glucose metabolism. This metabolic difference between cancer cells and normal cells could be exploited for therapeutic benefit in patients. Cancer cells universally express the M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2), and previous work has demonstrated that PKM2 expression is necessary for aerobic glycolysis and cell proliferation in vivo. Because most normal tissues express an isoform of pyruvate kinase other than PKM2, selective targeting of PKM2 provides an opportunity to target cell metabolism for cancer therapy. PKM2 has an identical catalytic site as the related M1 splice variant (PKM1). However, isoform selective inhibition is possible as PKM2 contains a unique region for allosteric regulation. We have screened a library of greater than 1,00,000 small molecules to identify such inhibitors. The inhibitors identified for PKM2 fell primarily into three distinct structural classes. The most potent PKM2 inhibitor resulted in decreased glycolysis and increased cell death following loss of growth factor signaling. At least part of this effect was due to on-target PKM2 inhibition as less cell death was observed in cells engineered to express PKM1. These data suggest that isoform selective inhibition of PKM2 with small molecules is feasible and support the hypothesis that inhibition of glucose metabolism in cancer cells is a viable strategy to treat human malignancy.

Approaching a complete repository of sequence-verified protein-encoding clones for Saccharomyces cerevisiae.

The availability of an annotated genome sequence for the yeast Saccharomyces cerevisiae has made possible the proteome-scale study of protein function and protein-protein interactions. These studies rely on availability of cloned open reading frame (ORF) collections that can be used for cell-free or cell-based protein expression. Several yeast ORF collections are available, but their use and data interpretation can be hindered by reliance on now out-of-date annotations, the inflexible presence of N- or C-terminal tags, and/or the unknown presence of mutations introduced during the cloning process. High-throughput biochemical and genetic analyses would benefit from a "gold standard" (fully sequence-verified, high-quality) ORF collection, which allows for high confidence in and reproducibility of experimental results. Here, we describe Yeast FLEXGene, a S. cerevisiae protein-coding clone collection that covers over 5000 predicted protein-coding sequences. The clone set covers 87% of the current S. cerevisiae genome annotation and includes full sequencing of each ORF insert. Availability of this collection makes possible a wide variety of studies from purified proteins to mutation suppression analysis, which should contribute to a global understanding of yeast protein function.