Expression of Kruppel-like factor 8 and Ki67 in lung adenocarcinoma and prognosis

Abnormal expression of Krüppel-like transcription factors and their potential values in lung cancer

Lung cancer still is one of the most common malignancy tumors in the world. However, the mechanisms of its occurrence and development have not been fully elucidated. Zinc finger protein family (ZNFs) is the largest transcription factor family in human genome. Recently, the more and more basic and clinical evidences have confirmed that ZNFs/Krüppel-like factors (KLFs) refer to a group of conserved zinc finger-containing transcription factors that are involved in lung cancer progression, with the functions of promotion, inhibition, dual roles and unknown classifications. Based on the recent literature, some of the oncogenic KLFs are promising molecular biomarkers for diagnosis, prognosis or therapeutic targets of lung cancer. Interestingly, a novel computational approach has been proposed by using machine learning on features calculated from primary sequences, the XGBoost-based model with accuracy of 96.4 % is efficient in identifying KLF proteins. This paper reviews the recent some progresses of the oncogenic KLFs with their potential values for diagnosis, prognosis and molecular target in lung cancer.

S-adenosylhomocysteine hydrolase-like protein 1 (AHCYL1) inhibits lung cancer tumorigenesis by regulating cell plasticity

BACKGROUND

Lung cancer is one of the most frequently diagnosed cancers characterized by high mortality, metastatic potential, and recurrence. Deregulated gene expression of lung cancer, likewise in many other solid tumors, accounts for their cell heterogeneity and plasticity. S-adenosylhomocysteine hydrolase-like protein 1 (AHCYL1), also known as Inositol triphosphate (IP(3)) receptor-binding protein released with IP(3) (IRBIT), plays roles in many cellular functions, including autophagy and apoptosis but AHCYL1 role in lung cancer is largely unknown.

RESULTS

Here, we analyzed the expression of AHCYL1 in Non-Small Cell Lung Cancer (NSCLC) cells from RNA-seq public data and surgical specimens, which revealed that AHCYL1 expression is downregulated in tumors and inverse correlated to proliferation marker Ki67 and the stemness signature expression. AHCYL1-silenced NSCLC cells showed enhanced stem-like properties in vitro, which correlated with higher expression levels of stem markers POU5F1 and CD133. Also, the lack of AHCYL1 enhanced tumorigenicity and angiogenesis in mouse xenograft models highlighting stemness features.

CONCLUSIONS

These findings indicate that AHCYL1 is a negative regulator in NSCLC tumorigenesis by modulating cell differentiation state and highlighting AHCYL1 as a potential prognostic biomarker for lung cancer.

The role of Krüppel-like factor 8 in cancer biology: Current research and its clinical relevance

Cancer is one of the leading causes of mortality worldwide, ranked second after heart disease. Despite recent advancements in diagnosis and treatment, there are still numerous problems associated with cancer progression, disease recurrence, and therapeutic resistance that are partially explored. Several studies have recently revealed that Krüppel-like factor 8 (KLF8) regulates transcription of genes linked with diverse biological processes, including proliferation, epithelial to mesenchymal transition (EMT), migration, invasion, and inflammation. KLF8 is expressed ubiquitously in mammalian cells, and its aberrant expression has been manifested with several cancer types. Earlier studies demonstrated the crucial role of KLF8 in DNA repair and resistance to apoptosis in numerous cancer types. Hence, studying the function of KLF8 from the perspective of cancer progression and therapy resistance would help develop a new therapeutic avenue. In this review, we summarize the clinical relevance of KLF8 expression in various malignancies, focusing on recent updates in EMT, cellular signaling, and cancer stem cells. We also address the contribution of KLF8 in development, DNA repair, chemoresistance, and its clinical utility as a predictive biomarker.

Hypermethylated KLF9 Is An Independent Prognostic Factor For Favorable Outcome In Breast Cancer

Background and objective

Breast cancer (BC) is the most lethal human malignancy and is the leading cause of cancer-associated death in women worldwide. Krüppel-like factor 9 (KLF9) belongs to a family of transcriptional regulators and its role in BC has not been fully investigated.

Method

Data mining was used to analyze BC data from The Cancer Genome Atlas (TCGA) database, which was downloaded using the UCSC Xena browser. The differential expression and methylation level of KLF9 was analyzed in patients with BC and corresponding normal controls enrolled from our hospital. Besides, the correlation of KLF9 methylation and prognosis was explored, and gene set enrichment analysis (GSEA) was conducted to identify the potential signaling pathway of KLF9 involved.

Results

Both TCGA and BC tissues indicated hypermethylation of the KLF9 promoter region in patients with BC compared with normal controls, which might account for the dysregulation of KLF9 in patients with BC. Besides, hypermethylation of KLF9 was detected in patients with estrogen or progesterone receptor-positive and non-triple-negative disease. Further, hypermethylation of KLF9 was demonstrated to be a potential independent biomarker in obtaining favorable outcomes in BC. By GSEA, tumor-associated biological processes and signaling pathway were identified, which indicated that KLF9 might play a vital role in the carcinogenesis of BC.

Conclusion

KFL9 plays an important role in the carcinogenesis of BC through the multiple tumor-associated signaling pathway. The hypermethylation of KLF9 resulted in its reduced expression in BC, while the hypermethylation of KLF9 has potential in the prediction of favorable outcomes in BC.

KLF8 overexpression promotes the growth of human lung cancer cells by promoting the expression of JMJD2A

Background

Non-small-cell lung cancer (lung cancer) has become one of the leading causes worldwide and the underlying mechanism is not fully understood. The transcriptional factor Kruppel like factor 8 (KLF8) is involved in the initiation, progression, transformation, and metastasis of diverse cancers. However, the roles of KLF8 in human non-small cell lung cancer remain unknown.

Methods

CCK-8 kit and colony formation assay were performed to determine the cell growth of lung cancer cells. Flow cytometry analysis was used to evaluate apoptosis and cell cycle of lung cancer cells. Luciferase reporter assay was used to examine the activation of JMJD2A promoter by KLF8. Chromatin immunoprecipitation assay was performed to evaluate the binding of KLF8 to JMJD2A promoter. Western blot and polymerase chain reaction were applied to analyze the expression of interested genes.

Results

The mRNA and protein levels of KLF8 in human non-small cell lung cancer tissues were overexpressed compared with the non-cancer tissues. KLF8 was knocked down with lentivirus-mediated short-hairpin RNA (shRNA) in human lung cancer cells (A549 and H1299 cells). The phenotypic results showed that KLF8 knockdown decreased the proliferation rate and colony formation of lung cancer cells. By contrast, lentivirus-mediated KLF8 overexpression promoted the growth of lung cancer cells (A549 and H1299 cells) and non-cancerous bronchial epithelial cell line BEAS-2B. Next, we showed that KLF8 regulated cell cycle at the G0 phase but not regulates cellular apoptosis of lung cancer cells. KLF8 regulated the expression of the cell cycle regulators P21 and CDK4 in a JMJD2A-dependent manner and JMJD2A knockdown significantly blocked the functions of KLF8 in regulating cell cycle and proliferation of lung cancer cells. Finally, we observed that KLF8 bound the promoter of JMJD2A and facilitated the expression of JMJD2A.

Conclusions

Our evidence demonstrated that KLF8 upregulation in human lung cancer promotes the cell proliferation and colony formation of lung cancer cells. KLF8 binds to the promoter of JMJD2A and subsequently regulates the expression of P21 and CDK4, which contributes to the regulation of cell cycle by KLF8. KLF8 may serve as a target for the treatment of human lung cancer.

The level of Krüppel-like factor 8 expression predicts prognosis and metastasis in various carcinomas

BACKGROUND AND OBJECTIVE

Krüppel-like factor 8 (KLF8), a transcription factor, belongs to the KLF8 family. Currently, studies have shown that KLF8 is highly expressed in some tumors. However, the prognostic value and metastasis of KLF8 in cancers remain unclear. For the first time, we conducted meta-analysis to explore the relationship between KLF8 expression with prognosis and metastasis in various carcinomas patients.

METHODS

Web of Science, PubMed, Embase, and Cochrane Library were systematically searched for eligible articles. Pooled hazard ratios (HRs) and their 95% confidence intervals (95% CIs) were calculated to evaluate the prognostic value and metastasis of KLF8 expression in human cancer patients.

RESULTS

The result revealed that highly expression level of KLF8 was significantly associated with poor overall survival (OS) (HR = 1.56, 95% CI: 1.26-1.87). Meanwhile, this significant correlation was also observed in subgroup analysis stratified by cancer types, source of HR, sample size, follow-up (months). In addition, highly expression of KLF8 was also closely associated with metastasis (HR = 1.37, 95% CI: 0.57-2.17) and tumor node metastasis stage (HR = 1.58, 95% CI: 0.90-2.25) in carcinomas.

CONCLUSION

In summary, our meta-analysis indicates that overexpression of KLF8 may be associated with poor prognosis and higher incidence of metastasis in various carcinomas, and KLF8 may be used as a prognostic and metastatic indicator in human cancers.

High FNDC1 expression correlates with poor prognosis in gastric cancer

Gastric cancer is a common human cancer worldwide. Fibronectin is an important extracellular matrix protein that has been implicated in many cancers and is known to be associated with proliferation and migration. Fibronectin type III domain containing 1 (FNDC1) contains a major component of the structural domain of fibronectin. The objectives of the present study were to measure FNDC1 expression in gastric cancer tissues and evaluate its value as a potential prognostic marker for gastric cancer. FNDC1 protein expression was analyzed by immunohistochemistry in 98 samples of gastric cancer tissue and 25 adjacent normal tissues. The associations between FNDC1 level and various clinicopathological characteristics were assessed, and the correlation between FNDC1 expression levels and prognosis of patients with gastric cancer was analyzed using a Kaplan-Meier analysis. It was demonstrated that FNDC1 expression in gastric cancer tissues and adjacent tissues was significantly different. FNDC1 expression levels were significantly higher in gastric cancer tissues compared with normal gastric tissues (P<0.001). Among the clinicopathological characteristics evaluated, clinical stage (P<0.001), T classification (P<0.001), N classification (P<0.001) and pathological differentiation (P=0.044) were significantly associated with high FNDC1 expression. Higher FNDC1 expression level was significantly correlated with poorer survival. The present findings suggest that FNDC1 expression levels may be a promising prognostic biomarker for gastric cancer.

KLF15 suppresses cell growth and predicts prognosis in lung adenocarcinoma

Krüppel-like factors (KLFs) are transcription factors containing three different C2H2-type zinc finger domains in their carboxy-terminal regions which have been identified to play important roles in a variety of cancers. However, little is known about KLF15 in lung adenocarcinoma (LAUD). Our study demonstrated that the expression levels of KLF15 were observably down-regulated in LAUD tissues compared to paired adjacent normal tissues. LUAD patients with low expression levels of KLF15 have worse prognosis than those with high expression levels of KLF15. KLF15 could suppress cell growth, which was partly via up-regulating CDKN1 A/p21 and CDKN2A/p15. Our findings suggested that KLF15 showed a significant role in LAUD progression and may shed light on a promising novel therapeutic target for blocking progression of LAUD.