Why is it in news?

Researchers at Delhi’s CSIR-Institute of Genomics and Integrative Biology (IGIB) have for the first time identified a calcium sensor protein (STIM1) that independently regulates both skin cancer and pigmentation. The STIM1 protein does so by activating two independent signalling pathways.

Details

• Different parts of the STIM1 protein activate the two independent signalling pathways that control melanoma growth and pigmentation. This opens up the possibility of developing drug molecules that target specific sites in the STIM1 protein to control tumour growth and regulate pigmentation.
• While skin cancers account for third highest number of cancer associated deaths worldwide, perturbations in pigmentation pathways result in pigmentation disorders such as solar lentigo, melasma, vitiligo, and pityriasis alba. Current therapeutic regimes are not efficient in alleviating pigmentation disorders.
• The role of STIM1 in breast cancer and prostate cancer is already known. Based on this, it was hypothesised that STIM1 might have a role in melanoma growth as well.
• To study the role of STIM1 protein in melanoma growth in vitro, the researchers used STIM1 knockdown mouse cells and injected them into mouse models and observed the growth of melanoma. Compared with controls, melanoma growth was reduced by as much as 75% in mice that were injected with STIM1 knockdown cells.
• While trying to find novel players that could potentially regulate pigmentation, the researchers identified a few signalling pathways which were differently regulated with change in pigmentation level.
• When chemicals were used to change the levels of pigmentation of melanocytes, the researchers found that along with changes in melanin levels, other signalling modules were also changing. Similarly, melanin level reduced when pigmentation decreased. A surprising finding was that when pigmentation was decreasing, the calcium signalling pathway was also decreasing.
• To confirm the role of STIM1 protein in pigmentation, the researchers knocked down the protein in melanocytes. This resulted in a reduction in pigmentation levels.
• The role of STIM1 was further validated by regulating pigmentation in zebrafish models.

Conclusion

This research can help in better targeting and killing of cancer cells for chemotherapy and could increase the rate of survival and recovery of cancer patients.

Source

The Hindu