Tumor-suppressive role of Kruppel-like factor 4 (KLF-4) in colorectal cancer.

Kruppel-like factors (KLFs) are a group of transcriptional regulators that have recently been identified to exhibit tumor-suppressive function against various gastrointestinal cancers. The present study aims to investigate the expression patterns and prognostic value of KLF-4 in colorectal cancers (CRCs). KLF-4 levels in CRC tissues were examined via immunohistochemistry analysis, real-time quantitative polymerase chain reaction, and western blotting. The chi-square test was performed to evaluate the correlation between KLF-4 expression and the clinicopathological characteristics. Kaplan-Meier analysis was performed to assess the prognostic value of KLF-4 in CRC patients. In addition, we evaluated the effect of KLF-4 knockdown on the proliferation of CRC HT-29 cells. Our results showed significant downregulation of KLF-4 in 31 CRC samples, collected from CRC patients showing more malignant characteristics such as lymphatic metastasis, low tumor cell differentiation, and tumor recurrence. CRC patients in the low KLF-4 group were found to have reduced overall survival and decreased disease-free survival time. Moreover, HT-29 cells transfected with siRNA-KLF-4 showed increased proliferation compared to those transfected with control siRNA. In summary, lower KLF-4 expression was correlated with malignant CRC status and poor prognosis in CRC patients. Moreover, KLF-4 suppression promoted the proliferation of CRC cells in vitro. These results provide novel insights into the tumor suppressive role of KLF-4 in CRC.

Characterization of a novel anther-specific gene encoding a leucine-rich repeat protein in petunia.

In Petunia x hybrida 'Fantasy Red', a leucine-rich repeat (LRR) gene referred to as PhLRR, was identified in a flower bud cDNA library. The open reading frame sequence of PhLRR was 1251 bp, encoding a putative 46.2-kDa protein of 416 amino acids. The PhLRR protein showed high similarity to members of polygalacturonase inhibitor proteins (PGIPs), contained 11 conserved LRR domains, and was an extracellular localization protein. Phylogenetic analysis showed that PhLRR belonged to the same PGIPs subfamily as SHY, indicating that PhLRR may be involved in the development of pollen-like SHY. Expression analysis revealed that PhLRR was abundantly expressed during early stages of flower bud and anther development, while it was not detected in any other examined organs, such as sepals, petals, pistils, roots, stems, leaves, or open flowers. Furthermore, many cis-acting elements (such as AGAAA and GTGA) related to anther-specific gene expression were identified in the PhLRR gene promoter region, indicating that the promoter is also anther-specific. These results suggested that PhLRR is a novel anther-specific gene that may be essential for the early development of anthers.