Common 4977 bp deletion and novel alterations in mitochondrial DNA in Vietnamese patients with breast cancer

Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, fluid coming from the nipple, or a red scaly patch of skin. In those with distant spread of the disease, there may be bone pain, swollen lymph nodes, shortness of breath, or yellow skin.

http://repository.vnu.edu.vn/handle/VNU_123/32403 

Risk factors for developing breast cancer include being female, obesity, lack of physical exercise, drinking alcohol, hormone replacement therapy during menopause, ionizing radiation, early age at first menstruation, having children late or not at all, older age, and family history. About 5–10% of cases are due to genes inherited from a person's parents, including BRCA1 and BRCA2 among others. Breast cancer most commonly develops in cells from the lining of milk ducts and the lobules that supply the ducts with milk. Cancers developing from the ducts are known as ductal carcinomas, while those developing from lobules are known as lobular carcinomas. In addition, there are more than 18 other sub-types of breast cancer. Some cancers, such as ductal carcinoma in situ, develop from pre-invasive lesions. The diagnosis of breast cancer is confirmed by taking a biopsy of the concerning lump. Once the diagnosis is made, further tests are done to determine if the cancer has spread beyond the breast and which treatments it may respond to.

Mitochondrial DNA (mtDNA) has been proposed to be involved in carcinogenesis and ageing. The mtDNA 4977 bp deletion is one of the most frequently observed mtDNA mutations in human tissues and may play a role in breast cancer (BC). The aim of this study was to investigate the frequency of mtDNA 4977 bp deletion in BC tissue and its association with clinical factors. We determined the presence of the 4977 bp common deletion in cancer and normal paired tissue samples from 106 Vietnamese patients with BC by sequencing PCR products. The mtDNA 4977 bp deletion was significantly more frequent in normal tissue in comparison with paired cancer tissue. Moreover, the incidence of the 4977 bp deletion in BC tissue was significantly higher in patients with estrogen receptor (ER) positive as compared with ER negative BC tissue. Preliminary results showed, in cancerous tissue, a significantly higher incidence of novel deletions in the group of patients with lymph node metastasis in comparison with the patients with no lymph node metastasis. We have found 4977 bp deletion in mtDNA to be a common event in BC and with special reference to ER positive BC. In addition, the novel deletions were shown to be related to lymph node metastasis. Our finding may provide complementary information in prediction of clinical outcome including metastasis, recurrence and survival of patients with BC.

Title: 

	Common 4977 bp deletion and novel alterations in mitochondrial DNA in Vietnamese patients with breast cancer
Authors:	Dimberg, Jan Trinh, Hong Thai Nguyen, Thi Linh Tu
Keywords:	Breast cancer Mitochondrial DNA mutation mtDNA deletion
Issue Date:	2015
Publisher:	SPRINGER INTERNATIONAL PUBLISHING AG, GEWERBESTRASSE 11, CHAM, CH-6330, SWITZERLAND
Citation:	ISIKNOWLEDGE
Abstract:	Mitochondrial DNA (mtDNA) has been proposed to be involved in carcinogenesis and ageing. The mtDNA 4977 bp deletion is one of the most frequently observed mtDNA mutations in human tissues and may play a role in breast cancer (BC). The aim of this study was to investigate the frequency of mtDNA 4977 bp deletion in BC tissue and its association with clinical factors. We determined the presence of the 4977 bp common deletion in cancer and normal paired tissue samples from 106 Vietnamese patients with BC by sequencing PCR products. The mtDNA 4977 bp deletion was significantly more frequent in normal tissue in comparison with paired cancer tissue. Moreover, the incidence of the 4977 bp deletion in BC tissue was significantly higher in patients with estrogen receptor (ER) positive as compared with ER negative BC tissue. Preliminary results showed, in cancerous tissue, a significantly higher incidence of novel deletions in the group of patients with lymph node metastasis in comparison with the patients with no lymph node metastasis. We have found 4977 bp deletion in mtDNA to be a common event in BC and with special reference to ER positive BC. In addition, the novel deletions were shown to be related to lymph node metastasis. Our finding may provide complementary information in prediction of clinical outcome including metastasis, recurrence and survival of patients with BC.
Description:	SPRINGERPLUS Volume: 4 Article Number: 58 Published: FEB 3 2015 ; TNS05760
URI:	https://springerplus.springeropen.com/articles/10.1186/s40064-015-0843-8 http://repository.vnu.edu.vn/handle/VNU_123/32403
ISSN:	2193-1801
Appears in Collections:	Bài báo của ĐHQGHN trong Web of Science