Study identifies new tumor suppressor

A protein called HLJ1 may work as a novel tumor suppressor in non-small-cell lung carcinoma, according to a study in the June 21 issue of the Journal of the National Cancer Institute.

Jeremy J.W. Chen, Ph.D., of National Chung-Hsing University, Pan-Chyr Yang, M.D., Ph.D., of National Taiwan University in Taiwan, and colleagues increased or blocked the expression of HLJ1 in lung carcinoma cells in the lab and examined the gene's expression in tumor and surrounding tissue cells of 71 patients with non-small-cell lung cancer. HLJ1 is a protein involved in a cell's defense mechanism against outside stress.

The authors observed that HLJ1 stopped proliferation of lung cancer cells, slowed the cell division cycle's progression, and inhibited the cells' ability to move and invade other tissues. In addition, HLJ1 expression was lower in tumor tissue than normal tissue in 55 of the 71 patients studied, and patients with high HLJ1 expressing tumors had reduced cancer recurrence and lived longer than those with low expressing tumors. The authors conclude that HLJ1 expression is a novel tumor suppressor in non-small-cell lung cancer. The authors write, "These findings may identify a subgroup of non-small-cell lung cancer patients who may benefit from adjuvant therapy and facilitate the design of individualized therapies for lung cancer."

In an accompanying editorial, Adriana Albini, Ph.D., and Ulrich Pfeffer, Ph.D., of the National Cancer Research Institute in Genova, Italy, write, "The article by [Chen and colleagues] will further stimulate scrutiny of the [proteins in the same family as HLJ1] and put cancer invasion, angiogenesis, and metastasis back on the list of functions inhibited by oncosuppressor genes in lung and perhaps other organs."

Contacts:

• Article: Pan-Chyr Yang, 886-2-23562905, pcyang@ha.mc.ntu.edu.tw
• Editorial: Adriana Albini, Adriana.Albini@istge.it

Citations:

• Article: Tsai M-F, Wang C-C, Chang G-C, Chen C-Y, Chen H-Y, Cheng C-L, et al. A New Tumor Suppressor DnaJ-Like Heat Shock Protein, HLJ1, and Survival of Patients With Non-Small-Cell Lung Carcinoma. J Natl Cancer Inst 2006; 98: 825-838.

• Editorial: Albini A, Pfeffer U. A New Tumor Suppressor Gene: Invasion, Metastasis, and Angiogenesis as Potential Key Targets. J Natl Cancer Inst 2006; 98: 800-801.

Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage. Visit the Journal online at http://jncicancerspectrum.oxfordjournals.org/.

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