Indian Science and Technology Developments : Updates and Discussions

Study opens new avenue for preventing cancer

Scientists have found a way to stop the degradation of a protein called p53 that prevents cancer cells from proliferating and forming tumors

By Sunderarajan Padmanabhan
Last Updated: Wednesday 25 September 2019

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In a new development in the area of cancer research, scientists at Delhi-based National Institute of Immunology (NII) have found a way to stop the degradation of a protein called p53 that prevents cancer cells from proliferating and forming tumors in the body.

p53 is one of the most well studied proteins in cancer biology. Like all proteins, its levels and activity are tightly controlled and they go through cycles of birth-existence-death: the protein is synthesised, it does its function and then it is degraded. When required, the protein is re-synthesised and the cycle keeps repeating.

Scientists across the world have been trying to find out how the level of p53 is regulated and what are the mechanisms underlying its degradation. The team of scientists at NII have now have shown that a protein called FBW7 is responsible for degrading p53. It degrades not only the wild type p53 but also mutant p53 version, which is involved in tumor promotion. As a validation of their finding, researchers haves hown that the half-life of p53 is increased and its function as tumor suppressor got enhanced in cancer cells that lacked FBW7.

The team has also worked out the mechanistic details of how FBW7α recognizes p53 and degrades it. Further, they have showed that the degradation happens as a result of damage to DNA induced by radiation and chemotherapy. Interestingly, FBW7 expression itself is dependent on p53 and it gets induced when cancer cells are exposed to DNA-damaging events. This indicates the presence of auto-regulatory loop in cells which tightly regulates the amount of p53 required to be present in the cells at any particular time.

“The results from our research provide novel ways of improving tumor regression by improving the function of p53 by stabilising its levels. This could be achieved by using a mutant of p53, which will not be degraded by FBW7α and may accentuate the therapeutic potential. Future work is needed to build on this startegy to find clinical application,” explained Sagar Sengupta, leader of the research team, while speaking to India Science Wire.

The study results have been published in the Journal of Biological Chemistry. The team included Vivek Tripathi, Ekjot Kaur, Suhas Sampat Kharat, Mansoor Hussain, Arun Prasath Damodaran and Swati Kulshrestha. The work was supported the Department of Biotechnology, Council of Scientific and Industrial Research, Science and Engineering Research Board and Department of Science and Technology. (India Science Wire)

Study opens new avenue for preventing cancer
 
Study paves the way for new approach to boost rice yield

The new development represents a new approach towards developing rice varieties that produce bigger and consequently heavier grains

By Sunderarajan Padmanabhan
Last Updated: Thursday 19 September 2019

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Rice productivity in India is low compared to other countries like China and Japan though it has the largest area under rice cultivation. Now scientists at the National Institute of Plant Genome Research (NIPGR) in New Delhi have identified a gene that is involved in regulating the size of rice grain.

The new development represents a new approach towards developing rice varieties that produce bigger and consequently heavier grains.
The researchers had found in earlier studies that expression of a particular gene, OsMed15a, was higher at different stages of seed development. The observation led them to explore its role further. They scanned 509 different rice genotypes and found that the nucleotide sequences of the OsMed15a gene varied depending on size of grain. OsMed15a was also found to play major role in regulating the expression of three other genes — GW2, GW5 and DR11I- which determine grain size and weight.

“When we suppressed the expression of OsMed15a in transgenic plants using RNAi technology, the seeds became smaller and wider,” said Jitender K Thakur, lead researcher, while speaking to India Science Wire. For further work, the group is collaborating with Ranchi-based Indian Institute of Agriculture Biotechnology so that grain size could be increased substantially through standard breeding methods.

“This study is important as it establishes OsMed15a as a connecting link between some of the different genes important for grain size / weight trait in rice. In the next phase, using high throughput ‘omics’ tools, we would be delineating complete network of genes and proteins being connected through OsMed51a,” Thakur said.

He also noted that the size and shape of the rice grain is not only important for boosting yield but also contributes to the market value of rice. “Indians prefer long and slender rice grains. There are some small grained rice which are full of pleasant aroma. We are trying to introgress long grain allele of OsMed15a in these varieties so that the seeds become longer. We hope that in this way we would be able to produce location-specific long grain aromatic rice”, he added.

The research team included Swarup K Parida, Nidhi Dwivedi, Sourobh Maji, Mohd Waseem, Pallabi Thakur and Vinay Kumar. The study results will be published in journal BBA — Gene Regulatory Mechanisms. This work was supported by grants from Science and Engineering Research Board (SERB) and Department of Biotechnology (DBT). (India Science Wire)

Study paves the way for new approach to boost rice yield