Prognostic Role of Krüppel-Like Factors 5, 9, and 11 in Endometrial Endometrioid Cancer

Identification of a novel tRNA-derived small RNA fragment, tRF-16-2YU04DE, with the potential of inhibiting endometrial cancer progression

As the second most prevalent gynecological malignancy, the incidence and mortality of endometrial cancer (EC) are rising. Transfer RNA-derived small RNAs (tsRNAs), a novel class of non-coding RNAs, are frequently dysregulated in multiple cancers. Nevertheless, its precise roles in EC remain to be elucidated. High-throughput sequencing technology was employed to characterize the expression profiles of tsRNAs in EC and healthy controls (HCs) tissues, followed by differential expression analyses. Quantitative real-time polymerase chain reaction (RT-qPCR) was applied to identify the target tsRNA for further biological functions experiments. Bioinformatics followed with RT-qPCR and Western blot systematically explore potential target genes and delineated the underlying molecular mechanisms. Eventually, a total of 284 tsRNAs were identified in both EC and HC tissues with 26 upregulated and 47 downregulated significantly. tRF-16-2YU04DE was finally identified as the target molecule. Functional experiments revealed that the overexpression of tRF-16-2YU04DE not only inhibited the proliferation, migration, and invasion of EC cells, but also promoted apoptosis and disrupted cell cycle progression. Although the downregulation of tRF-16-2YU04DE significantly promotes the proliferation, migration, and invasion of EC cells, it does not have a notable effect on cell apoptosis or the cell cycle. Bioinformatics analyses combined with RT-qPCR and Western blot results showed KLF5 expression was particularly downregulated by the overexpression of tRF-16-2YU04DE. tRF-16-2YU04DE-inhibiting EC progression in vitro may serve as a promising therapeutic target. The underlying mechanism is likely linked to its RNA silencing function, specifically targeting the 3' untranslated region (3' -UTR) of KLF5 mRNA.

Variants of KLF5 and KLF12 were related to endometrial cancer risk in the Chinese population

OBJECTIVES

Krüppel‑like factors (KLFs) are implicated in the progression of endometrial cancer (EC). This present study explored the correlation between variants of KLF5, KLF12 and EC risk in the Chinese population.

METHODS

The Agena MassARRAY technology platform was utilized to genotype six single nucleotide polymorphisms (SNPs) in KLF5 and KLF12 genes among 509 women diagnosed with EC and 506 age-matched healthy women. Subsequently, the relationship between SNPs in KLF5 and KLF12 and EC risk was calculated using logistic regression analysis. The interactions between SNPs in KLF5 and KLF12 were analyzed to predict EC risk using multifactor dimensionality reduction (MDR) analysis.

RESULTS

KLF12 rs12429889 was significantly associated with EC risk (codominant: OR = 1.53, p = 0.003; dominant: OR = 1.54, p = 0.004). In addition, rs7329599 was significantly associated with EC risk in participants aged ≤55 years (codominant: OR = 0.63, p = 0.014; dominant: OR = 0.67, p = 0.024), whereas rs12429889 was significantly associated with EC risk in participants aged >55 years (codominant: OR = 1.98, p = 0.004; dominant: OR = 2.06, p = 0.002).

CONCLUSION

Our findings revealed a significant correlation between KLF12 rs12429889 and rs7329599 and EC risk, highlighting their potential as diagnostic biomarkers. [Figure: see text].

KLF11 promotes the proliferation of breast cancer cells by inhibiting p53-MDM2 signaling

Abnormal Krüppel-like factor 11 (KLF11) expression is frequently found in tumor tissues and is associated with cancer prognosis, but its biological functions and corresponding mechanisms remain elusive. Here, we demonstrated that KLF11 functions as an oncoprotein to promote tumor proliferation in breast cancer cells. Mechanistically, at the transcription level, KLF11 decreased TP53 mRNA expression. Notably, KLF11 also interacted with and stabilized MDM2 through inhibiting MDM2 ubiquitination and subsequent degradation. This increase in MDM2 in turn accelerated the ubiquitin-mediated proteolysis of p53, leading to the reduced expression of p53 and its target genes, including CDKN1A, BAX, and NOXA1. Accordingly, data from animals further confirmed that KLF11 significantly upregulated the growth of breast cancer cells and was inversely correlated with p53 expression. Taken together, our findings reveal a novel mechanism for breast cancer progression in which the function of the tumor suppressor p53 is dramatically weakened.

KLF9‑regulated FBXO31 inhibits the progression of endometrial cancer and enhances the sensitivity of endometrial cancer cells to cisplatin

Endometrial cancer (EC) is one of the most common malignancies with an increasing annual incidence. F-box only protein 31 (FBXO31) plays a significant regulatory role in several types of cancer. The transcription factor Krüppel-like factor 9 (KLF9) of FBXO31 is reduced in EC as a tumor suppressor. However, their particular regulatory role and mechanism in EC have not been previously reported. Therefore, the UALCAN database was used to predict the expression levels of FBXO31 in EC. In addition, the regulatory effect of FBXO31 on EC cell proliferation, invasion, migration, apoptosis and cisplatin (DDP) sensitivity was investigated at the cellular level. The association between KLF9 and FBXO31 was predicted using the JASPAR database and verified by chromatin immunoprecipitation and luciferase reporter assays. Finally, the regulatory effects of KLF9 and FBXO31 overexpression or silencing were also explored. The results demonstrated that FBXO31 was poorly expressed in EC. Additionally, FBXO31 overexpression inhibited the malignant progression of EC cells and enhanced their sensitivity to DDP. Furthermore, KLF9 promoted FBXO31 transcription. Overall, the present study suggested that the KLF9-mediated regulation of FBXO31 could inhibit the progression of EC and enhance the sensitivity of EC cells to DDP.

A nomogram for predicting recurrence in endometrial cancer patients: a population-based analysis

Objective

Endometrial cancer recurrence is one of the main factors leading to increased mortality, and there is a lack of predictive models. Our study aimed to establish a nomogram predictive model to predict recurrence in endometrial cancer patients.

Method

Screen 517 endometrial cancer patients who came to Nanjing Drum Tower Hospital from 2008 to 2018. All these data are listed as the training group, and then 70% and 60% are randomly divided into verification groups 1 and 2. Univariate, Multivariate logistic regression, stepwise regression were used to select variables for nomogram. Nomogram identification and calibration were evaluated by concordance index (c-index), area under receiver operating characteristic curve (AUC) over time and calibration plot Function. By decision curve analysis (DCA), net reclassification index (NRI), integrated discrimination improvement (IDI), we compared and quantified the net benefit of nomogram and ESMO-ESGO-ESTRO model-based prediction of tumor recurrence.

Results

A nomogram predictive model of endometrial cancer recurrence was established with the eight variables screened. The c-index (for the training cohort and for the validation cohort) and the time-dependent AUC showed good discriminative power of the nomogram. Calibration plots showed good agreement between nomogram predictions and actual observations in both the training and validation sets.

Conclusions

We developed and validated a predictive model of endometrial cancer recurrence to assist clinicians in assessing recurrence in endometrial cancer patients.

The induction of ferroptosis by KLF11/NCOA4 axis: the inhibitory role in clear cell renal cell carcinoma

Ferroptosis is a form of cell death and has great potential application in the treatment of many cancers, including clear cell renal cell carcinoma (ccRCC). Herein, we identified the essential roles of Krüppel-like factor 11 (KLF11) in suppressing the progression of ccRCC. By analyzing mRNA expression data from the Gene Expression Omnibus (GEO) database, we found that KLF11 was a significantly downregulated gene in ccRCC tissues. The results of subsequent functional assays verified that KLF11 played an antiproliferative role in ccRCC cells and xenograft tumors. Furthermore, gene set enrichment analysis indicated that ferroptosis was involved in ccRCC development, and correlation analysis revealed that KLF11 was positively related to ferroptosis drivers. We also found that KLF11 promoted ferroptosis in ccRCC by downregulating the protein expression of ferritin, system xc (-) cystine/glutamate antiporter (xCT), and glutathione peroxidase 4 (GPX4), acting as the inhibitory factors of ferroptosis and increasing the intracellular levels of lipid reactive oxygen species (ROS). As a transcriptional regulator, KLF11 significantly increased the promoter activity of nuclear receptor coactivator 4 (NCOA4), a gene significantly downregulated in ccRCC and whose low expression is associated with poor survival. The characteristics of ccRCC cells caused by KLF11 overexpression were reversed after NCOA4 silencing. In summary, the present study suggests that KLF11 suppresses the progression of ccRCC by increasing NCOA4 transcription. Therefore, the KLF11/NCOA4 axis may serve as a novel therapeutic target for human ccRCC.

An implementation of the learning curve cumulative summation test to evaluate a practicum for endometrial cancer ultrasound staging

PURPOSE

The learning curve cumulative summation (LC-CUSUM) test is commonly used as a quantitative assessment of the individual learning process. This study aimed to evaluate the skill acquisition process for performing ultrasound staging of endometrial cancer using the LC-CUSUM test.

METHODS

Sixty-seven ultrasound examinations performed by two operators were evaluated using the LC-CUSUM test according to their rate of success or failure to correctly stage myometrial invasion, serosa involvement, and pelvic and para-aortic lymph node involvement. The reference standard was the pathologic result. After the learning phase, the cumulative summation (CUSUM) test was applied to assess performance maintenance.

RESULTS

The processes achieved satisfactory performance in the majority of the cases according to the established definitions. Operator 1 reached adequate performance within the 30th procedure for all the locations considered, while operator 2 performed fewer than 30 ultrasound examinations by the audit time. The CUSUM test confirmed that the target quality was preserved after the learning phase. Moreover, the ultrasound staging for endometrial cancer was highly accurate.

CONCLUSION

Using the LC-CUSUM test made it possible to monitor the achievement and maintenance of a satisfactory performance quantitatively. The LC-CUSUM test could be a valuable instrument to survey diagnostic pathways in gynecological ultrasonography quantitatively.

Quantification of Women Who Could Benefit from Hormone Therapy after Endometrial Cancer Treatment: An Analysis of SEER Data

Our primary aim was to estimate the magnitude of stage I endometrial cancer (EC) survivors that could benefit from hormonal therapy (HT). Our secondary aims were to assess EC incidence in women below 50 and below 60 over the years, and analyze the overall survival and any influencing factors. We analyzed the endometrioid EC data from the Surveillance, Epidemiology, and End Results (SEER) program according to women's age, tumor stage, and grade. We analyzed the proportions of EC survivors below 50 and below 60 years of age and stratified those age groups by race. For age distribution and survival analysis SEER, 18 registries' research data (2000-2018) were analyzed. We analyzed the SEER 12 registries' research data (1992-2019) for incidence time trends. Our investigation found a 14% and 40% cumulative prevalence of stage I EC that occurs in women below 50 or 60 years, respectively. EC's prevalence has progressively risen in recent decades, but cancer-specific mortality remains low. The increasing number of women affected by EC in premenopause or early postmenopause face an 18 years-survival rate of 96.86% and 95.73%, respectively. A significant proportion of low-grade EC survivors can potentially benefit from HT treatment, and this requires awareness of other aspects of their health or quality of life, in addition to cancer treatments.

Survivin, Sonic hedgehog, Krüppel-like factors, and p53 pathway in serous ovarian cancer: an immunohistochemical study

OBJECTIVE

Survivin was previously associated with tumor stage and grade in ovarian cancer and interfered with the tumor's drug sensitivity. In addition, Survivin expression was found to be regulated by the Sonic hedgehog (Shh) pathway, Krüppel-like factor (KLF) family proteins, and p53 pathway. The main aim of this study was to assess the prognostic values of immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a cohort of high grade ovarian serous cancers. Other aims were comparison between high- and low-grade ovarian serous cancer and between platinum-resistant and the other cases. The last aim was to assess the correlations among the immunohistochemical expression of the studied proteins.

METHODS

Retrospective cohort study to assess immunohistochemical expression of Survivin, Klf5, Klf11, Shh, p53, p21, and Mdm2 in a tissue microarray of primary tumor samples among 73 women affected by high-grade ovarian serous cancer and 9 by low-grade ovarian serous cancer.

RESULTS

Klf5 and Shh cytoplasmic staining were associated to short overall survival (HR 6.38, CI.95 2.25 - 18.01, p<0.05 and 2.25, CI.95 1.19-4.23, p<0.05 respectively). In addition, cytoplasmic Klf5 staining, high Klf11 and p53 nuclear staining were associated with platinum resistance (p<0.05). Cytoplasmic Shh score was significantly correlated to the immunohistochemical expression of Klf5, Klf11, Mdm2, and Survivin.

CONCLUSIONS

Our data highlight the possible role of Klf5 and Shh as prognostic markers, meanwhile confirming the role of the KLF family proteins and p53 in ovarian cancer drug resistance. Moreover, Shh appeared to play an important role in the intracellular network of ovarian neoplasia.

miR-600 promotes ovarian cancer cells stemness, proliferation and metastasis via targeting KLF9

Previous studies have revealed that miRNAs participate in the pathogenesis of ovarian cancer; however, whether miR-600 is also involved remains unclear. In this study, we aimed to investigated the role of miR-600 in ovarian cancer progression. Here, miR-600 expression was significantly upregulated in ovarian cancer tissues and stem cells. Functional studies showed that miR-600 promoted ovarian cancer cell stemness, proliferation and metastasis. Mechanistic studies revealed that Kruppel like factor 9 (KLF9) was indicated as the target of miR-600. The luciferase reporter assay suggested that miR-600 directly bound to the 3'-untranslated region of KLF9. Additionally, miR-600 expression was negatively associated with KLF9 expression in human ovarian cancer tissues. Si-KLF9 partially abolished the discrepancy of self-renewal, growth and metastasis capacity between miR-600 knockdown ovarian cancer cells and control cells. In conclusion, our results suggest that miR-600 promotes ovarian cancer cell stemness, proliferation and metastasis via directly downregulating KLF9, and impairing miR-600 levels may be a new treatment strategy for ovarian cancer in the future.

KLF11 promotes the progression of glioma via regulating HJURP

Understanding the molecular mechanism of glioma is very important for the diagnosis and treatment of glioma. Recently, a new study illustrated that KLF11 could be a potential prognostic and diagnostic biomarker in glioma, but the critical role is not illustrated. In this paper, we found that KLF11 was highly expressed in glioma cancer tissues and cells, and KLF11 high expression of glioblastoma (GBM) and Lower-grade glioma (LGG) were correlated with poorer overall survival and disease-free survival percentages. KLF11 knockdown inhibited glioma cell proliferation and migration, while KLF11 overexpression enhanced cell proliferation and migration. In vivo, knockdown of KLF11 reduced the tumor size of glioma. With regard to the molecular regulatory mechanism, we clarified that the Holliday Junction Recognition Protein (HJURP) was positively regulated by KLF11. Meanwhile, we demonstrated that HJURP knockdown also inhibited glioma carcinoma progression. Overexpression of HJURP rescued the suppressed proliferation and migration function of glioma cells with depletion of KLF11. Therefore, our study demonstrated the function of KLF11 in glioma and showed KLF11 and HJURP could be prognostic and diagnostic markers in glioma, which provides a new insight of glioma therapy. This article is protected by copyright. All rights reserved.

The functions and prognostic value of Krüppel-like factors in breast cancer

Background

Krüppel‐like factors (KLFs) are zinc finger proteins which participate in transcriptional gene regulation. Although increasing evidence indicate that KLFs are involved in carcinogenesis and progression, its clinical significance and biological function in breast cancer are still limited.

Methods

We investigated all the expression of KLFs (KLF1-18) at transcriptional levels by using Oncomine and Gene Expression Profiling Interactive Analysis (GEPIA). The mRNA and protein expression levels of KLFs were also determined by using RT-qPCR and immunohistochemistry, respectively. CBioPortal, GeneMANIA and STRING were used to comprehensive analysis of the molecular characteristics of KLFs. The clinical value of prognostic prediction based on the expression of KLFs was determined by using the KM plotter. The relevant molecular pathways of KLFs were further analyzed by using Gene Set Enrichment Analysis (GSEA) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Finally, we investigated the effect of KLF2 and KLF15 on biological behavior of breast cancer cells in vitro.

Results

The expression of KLF2/4/6/8/9/11/15 was significantly down-regulated in breast cancer. The patients with high KLF2, KLF4 or KLF15 expression had a better outcome, while patients with high KLF8 or KLF11 had a poor prognosis. Furthermore, our results showed that KLF2 or KLF15 can be used as a prognostic factor independent on the other KLFs in patients with breast cancer. Overexpression of KLF2 or KLF15 inhibited cell proliferation and migration, and blocked cell cycle at G0/G1 phase, resulting in cell apoptosis.

Conclusions

KLF2 and KLF15 function as tumor suppressors in breast cancer and are potential biomarkers for prognostic prediction in patients with breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02449-6.

MiR-10b-3p alleviates cerebral ischemia/reperfusion injury by targeting Krüppel-like factor 5 (KLF5)

Although miR-10b-3p has been identified to be involved in cerebral ischemia injury, its impact and specific mechanism in cerebral ischemia injury remain unclear. The effects of Mir-10b-3p were investigated by establishing rat and cell models of ischemia/reperfusion (I/R) injury. Oxygen-glucose deprivation/reperfusion (OGD/R) was performed on pheochromocytoma-12 (PC12) cells. MiR-10b-3p expression levels in brain tissues and PC12 cells were detected by qRT-PCR. The impacts of miR-10b-3p on neurological deficits, infarct volume, inflammatory factor expression, in vivo brain water content, cell viability, and cell apoptosis were assessed. The relationship between miR-10b-3p and KLF5 was determined by TargetScan and luciferase reporter assay. The rescue experiments were performed to confirm the role of this axis in cerebral ischemia injury. Mir-10b-3p levels in rat brain tissue and PC12 cells were significantly decreased after I/R injury. MiR-10b-3p overexpression obviously reduced neurological deficits, infarct volume, brain water content, inflammatory factors expression, and neuronal apoptosis in the brain of ischemia-stroked rats. Meanwhile, miR-10b-3p upregulation also inhibited cell viability and apoptosis of OGD/R-induced PC12 cells. Besides, KLF5 was identified as a target of miR-10b-3p, and rescue experiments revealed that KLF5 was involved in the regulation of miR-10b-3p in ischemic injury. Our results demonstrated that miR-10b-3p had the neuroprotective effects against ischemia injury by targeting KLF5 and provided a potential underlying target for ischemic stroke treatment.

KLF9 suppresses cell growth and induces apoptosis via the AR pathway in androgen-dependent prostate cancer cells

Kruppel-like factors (KLFs) play an important role in many biological processes including cell proliferation, differentiation and development. Our study showed that the level of KLF9 is lower in PCa cell lines compared to a benign prostate cell line; the androgen-independent cell line PC3 expresses significantly lower KLF9 than the androgen-dependent cell line, LNCaP. Forced overexpression of KLF9 suppressed cell growth, colony formation, and induced cell apoptosis in LNCaP cells. We also found that KLF9 expression was induced in response to apoptosis caused by flutamide, and further addition of dihydrotestosterone antagonized the action of flutamide and significantly decreased KLF9 expression. Furthermore, activation of the androgen receptor (AR) was inhibited by the overexpression of KLF9. Our research shows that KLF9 is lower in androgen-independent cell lines than in androgen-dependent cell lines; Overexpression of KLF9 dramatically suppresses the proliferation, anchorage-independent growth, and induces apoptosis in androgen-dependent cells; KLF9 inhibition on prostate cancer cell growth may be acting through the AR pathway. Our results therefore suggest that KLF9 may play a significant role in the transition from androgen-dependent to androgen-independent prostate cancer and is a potential target of prevention and therapy.

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KLF9 is lower in androgen-independent cell lines than in androgen-dependent cell lines.

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Overexpression of KLF9 suppresses the proliferation and induces apoptosis in androgen-dependent cells.

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KLF9 inhibition on androgen-dependent Pca growth may be associated with the inhibition of AR pathway.