Oncogene database

9928

KIF14

kinesin family member 14;KIF14;kinesin family member 14

kinesin-like protein KIF14

1q32.1

protein-coding

Gain of chromosome 1q31-1q32 is seen in >50% of retinoblastoma and is common in other tumors. To define the minimal 1q region of gain, we determined genomic copy number by quantitative multiplex PCR of 14 sequence tagged sites (STSs) spanning 1q25.3-1q41. The most frequently gained STS at 1q32.1 (71%; 39 of 55 retinoblastoma) defined a 3.06 Mbp minimal region of gain between flanking markers, containing 14 genes. Of these, only KIF14, a putative chromokinesin, was overexpressed in various cancers by real-time RT-PCR. KIF14 mRNA was expressed in 20/22 retinoblastoma samples 100-1000-fold higher than in retina (t-test P=0.00002); cell lines (n=10) had higher levels than tumors (n=12) (P=0.009). KIF14 protein was overexpressed in retinoblastoma tumors and breast cancer cell lines by immunoblot. KIF14 was expressed in 4/4 breast cancer cell lines 31-92-fold higher than in normal breast tissue, in 5/5 medulloblastoma cell lines 22-79-fold higher than in fetal brain, and in 10/22 primary lung tumors 3-34-fold higher than in normal lung. Patients with lung tumors that overexpress KIF14 showed a trend toward decreased survival. KIF14 may thus be important in oncogenesis, and has promise as a prognostic indicator and therapeutic target.

The identification of breast ductal carcinoma in situ (DCIS) is a factor that increases 8-10 times the risk of developing invasive ductal breast carcinoma (DCI) later. In this study, we evaluated the immunoexpression of the HER2/neu oncoprotein in the DCIS cases associated with DCI, both in situ and in the invasive components. We also studied the Her2/neu immunoreactivity in the cases of DCI having no DCIS association. The positive immunoreactivity (score 3) of the HER2/neu oncoprotein was present in 29 cases of high-grade DCIS having DCI associated, corresponding to the histological types comedo, solid, comedo/solid, and micropapillary. A weak-to-moderate complete membrane staining (score 2+) was determined in five high-grade DCIS and four intermediate-grade DCIS cases, belonging to the types comedo, solid, and micropapillary. The negative immunoreactivity of HER2/neu was identified in 18 cases, most of them being of low grade and belonging to the solid and cribriform types. The invasive component of the analyzed lesions indicated a HER2/neu positive reaction in 50% of lesions having DCI associated and 17.4% of the lesions having no DCIS association. The DCIS-DCI association and the DCIS histological types that were analyzed through the HER2/immunoexpression can stand as prognostic factors for the malignant breast lesions.