TY - JOUR
T1 - Biological and clinical significance of loss of heterozygosity at the INPP4B gene locus in Japanese breast cancer
AU - Tokunaga, Eriko
AU - Yamashita, Nami
AU - Kitao, Hiroyuki
AU - Tanaka, Kimihiro
AU - Taketani, Kenji
AU - Inoue, Yuka
AU - Saeki, Hiroshi
AU - Oki, Eiji
AU - Oda, Yoshinao
AU - Maehara, Yoshihiko
N1 - Funding Information:
We are grateful to Ms. Y. Kubota, Ms. T. Shishino and Ms. N. Makikusa for their valuable technical assistance. This study was supported by grants from the Ministry of Education, Culture, Sports Science, and Technology of Japan (Grant No. 23591896 ).
PY - 2016/2/1
Y1 - 2016/2/1
N2 - Purpose: INPP4B is considered to function as a putative tumor suppressor through its inhibitory function of Akt. In various malignant tumors, loss of heterozygosity (LOH) at the chromosomal region containing INPP4B and lower expression of INPP4B has been reported. The purpose of this study was to examine the frequency of the INPP4B LOH and its association with the clinicopathological characteristics and prognosis in breast cancer of Japanese women. Methods: The allelic alteration at the INPP4B and PTEN gene loci was analyzed in 277 invasive primary breast carcinomas. The relationships between INPP4B LOH and the clinicopathological features were investigated. Results: Among the 238 informative cases for the evaluation, LOH at the INPP4B gene locus was observed in 43 tumors (18.1%). INPP4B LOH was significantly correlated with ER and PR negativity (p = 0.0009 and p = 0.0029, respectively), higher nuclear grade (p < 0.0001), higher Ki67 labeling index (p = 0.0006), triple-negative (TN) subtype (p = 0.0005) and PTEN LOH (p < 0.0001). INPP4B LOH was significantly associated with poorer prognosis, in terms of the relapse-free survival (RFS) and overall survival (OS). According to the multivariate analyses, INPP4B LOH was not independently associated with the prognosis. Conclusion: The incidence of INPP4B LOH was significantly higher in the TN subtype and positively correlated with PTEN LOH. INPP4B LOH was associated with more aggressive and proliferative phenotype. INPP4B LOH was also associated with poorer prognosis.
AB - Purpose: INPP4B is considered to function as a putative tumor suppressor through its inhibitory function of Akt. In various malignant tumors, loss of heterozygosity (LOH) at the chromosomal region containing INPP4B and lower expression of INPP4B has been reported. The purpose of this study was to examine the frequency of the INPP4B LOH and its association with the clinicopathological characteristics and prognosis in breast cancer of Japanese women. Methods: The allelic alteration at the INPP4B and PTEN gene loci was analyzed in 277 invasive primary breast carcinomas. The relationships between INPP4B LOH and the clinicopathological features were investigated. Results: Among the 238 informative cases for the evaluation, LOH at the INPP4B gene locus was observed in 43 tumors (18.1%). INPP4B LOH was significantly correlated with ER and PR negativity (p = 0.0009 and p = 0.0029, respectively), higher nuclear grade (p < 0.0001), higher Ki67 labeling index (p = 0.0006), triple-negative (TN) subtype (p = 0.0005) and PTEN LOH (p < 0.0001). INPP4B LOH was significantly associated with poorer prognosis, in terms of the relapse-free survival (RFS) and overall survival (OS). According to the multivariate analyses, INPP4B LOH was not independently associated with the prognosis. Conclusion: The incidence of INPP4B LOH was significantly higher in the TN subtype and positively correlated with PTEN LOH. INPP4B LOH was associated with more aggressive and proliferative phenotype. INPP4B LOH was also associated with poorer prognosis.
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U2 - 10.1016/j.breast.2015.10.006
DO - 10.1016/j.breast.2015.10.006
M3 - Article
C2 - 26577950
AN - SCOPUS:84959160558
VL - 25
SP - 62
EP - 68
JO - Breast
JF - Breast
SN - 0960-9776
ER -