Prognostic Value of the FOXK Family Expression in Patients with Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiotherapy

FOXK2 targeting by the SCF-E3 ligase subunit FBXO24 for ubiquitin mediated degradation modulates mitochondrial respiration

FOXK2 is a crucial transcription factor implicated in a wide array of biological activities and yet understanding of its molecular regulation at the level of protein turnover is limited. Here, we identify that FOXK2 undergoes degradation in lung epithelia in the presence of the virulent pathogens Pseudomonas aeruginosa and Klebsiella pneumoniae through ubiquitin-proteasomal processing. FOXK2 through its carboxyl terminus (aa 428-478) binds the Skp-Cullin-F-box ubiquitin E3 ligase subunit FBXO24 that mediates multisite polyubiquitylation of the transcription factor resulting in its nuclear degradation. FOXK2 was detected within the mitochondria and targeted depletion of the transcription factor or cellular expression of FOXK2 mutants devoid of key carboxy terminal domains significantly impaired mitochondrial function. In experimental bacterial pneumonia, Fbxo24 heterozygous mice exhibited preserved mitochondrial function and Foxk2 protein levels compared to WT littermates. The results suggest a new mode of regulatory control of mitochondrial energetics through modulation of FOXK2 cellular abundance.

Regulation and roles of FOXK2 in cancer

Forkhead box K2 (FOXK2) is a member of the forkhead box transcription factor family that contains an evolutionarily conserved winged-helix DNA-binding domain. Recently, an increasing number of studies have demonstrated that FOXK2 plays an important role in the transcriptional regulation of cancer. Here, we provide an overview of the mechanisms underlying the regulation of FOXK2 expression and function and discuss the roles of FOXK2 in tumor pathogenesis. Additionally, we evaluated the prognostic value of FOXK2 expression in patients with various cancers. This review presents an overview of the different roles of FOXK2 in tumorigenesis and will help inform the design of experimental studies involving FOXK2. Ultimately, the information presented here will help enhance the therapeutic potential of FOXK2 as a cancer target.

Tissue-Based Markers as a Tool to Assess Response to Neoadjuvant Radiotherapy in Rectal Cancer-Systematic Review

According to current guidelines, the current treatment for locally advanced rectal cancer is neoadjuvant therapy, followed by a total mesorectal excision. However, radiosensitivity tends to differ among patients due to tumor heterogeneity, making it difficult to predict the possible outcomes of the neoadjuvant therapy. This review aims to investigate different types of tissue-based biomarkers and their capability of predicting tumor response to neoadjuvant therapy in patients with locally advanced rectal cancer. We identified 169 abstracts in NCBI PubMed, selected 48 reports considered to meet inclusion criteria and performed this systematic review. Multiple classes of molecular biomarkers, such as proteins, DNA, micro-RNA or tumor immune microenvironment, were studied as potential predictors for rectal cancer response; nonetheless, no literature to date has provided enough sufficient evidence for any of them to be introduced into clinical practice.

Long non-coding RNA tumor protein 53 target gene 1 promotes cervical cancer development via regulating microRNA-33a-5p to target forkhead box K2

Long non-coding RNA tumor protein 53 target gene 1 (TP53TG1) has been unraveled to exert regulatory effects on cancer progression, while the regulatory function of TP53TG1 on cervical cancer (CC) via regulating microRNA (miR)-33a-5p/Forkhead box K2 (FOXK2) axis remains rarely explored. This study aims to unearth the regulatory mechanism of TP53TG1/miR-33a-5p/FOXK2 axis in CC. The CC clinical samples were collected, and CC cells were cultured. TP53TG1, miR-33a-5p and FOXK2 levels were examined in CC tissues and cells. The CC cells were transfected with high- or low-expressed TP53TG1, FOXK2 or miR-33a-5p to determine the changes of CC cell biological activities and the status of phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. The tumorigenesis in nude mice was conducted. The relationship among TP53TG1, miR-33a-5p and FOXK2 was validated. TP53TG1 and FOXK2 expression levels were increased and miR-33a-5p expression level was reduced in CC cells and tissues. The silenced TP53TG1 or FOXK2, or elevated miR-33a-5p decelerated the CC cell development and restrained the activation of PI3K/AKT/mTOR signaling pathway. The depleted FOXK2 or elevated miR-33a-5p reversed the effects of decreased TP53TG1 on CC cell progression. TP53TG1 sponged miR-33a-5p, which targeted FOXK2. The experiment in vivo validated the outcomes of the experiment in vitro. TP53TG1 accelerates the CC development via regulating miR-33a-5p to target FOXK2 with the involvement of PI3K/AKT/mTOR signaling pathway. This study provides novel theory basis and distinct therapeutic targets for CC treatment.

Predicting response to neoadjuvant chemoradiotherapy in rectal cancer: from biomarkers to tumor models

Colorectal cancer (CRC) is a major contributor to cancer-associated morbidity worldwide and over one-third of CRC is located in the rectum. Neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection is commonly applied to treat locally advanced rectal cancer (LARC). In this review, we summarize current and novel concepts of neoadjuvant therapy for LARC such as total neoadjuvant therapy and describe how these developments impact treatment response. Moreover, as response to nCRT is highly divergent in rectal cancers, we discuss the role of potential predictive biomarkers. We review recent advances in biomarker discovery, from a clinical as well as a histopathological and molecular perspective. Furthermore, the role of emerging predictive biomarkers derived from the tumor environment such as immune cell composition and gut microbiome is presented. Finally, we describe how different tumor models such as patient-derived cancer organoids are used to identify novel predictive biomarkers for chemoradiotherapy (CRT) in rectal cancer.

Predicting Neoadjuvant Chemoradiotherapy Response in Locally Advanced Rectal Cancer Using Tumor-Infiltrating Lymphocytes Density

PURPOSE

Accumulating evidence revealed the predictive value of tumor-infiltrating lymphocytes (TILs) for neoadjuvant chemoradiotherapy (nCRT) response in solid tumors. This study quantified TILs density using hematoxylin and eosin (H&E) stained whole-slide images (WSIs) and investigated the predictive value of TILs density on nCRT response in locally advanced rectal cancer (LARC) patients.

PATIENTS AND METHODS

Two hundred and ten patients diagnosed with LARC were enrolled in this study. The density of TILs in the stroma region was quantified by a semi-automatic method in WSIs. Patients were stratified into low-TILs and high-TILs groups using the median value as the threshold. The tumor regression grade (TRG) was used to assess the response to nCRT in tumor resected specimens. Based on TRG, patients were classified into major-responder (TRG 0-1) and non-responder (TRG 2-3) groups.

RESULTS

The TILs density was significantly correlated with the nCRT response. Specifically, patients with high-TILs tend to have a higher major-responder rate than the low-TILs group (63.8% vs 47.6%, P = 0.026). Univariate analysis showed the TILs density was a predictor for the nCRT response (high vs low, odds ratio [OR] =1.94, 95% confidence interval 1.12-3.37, P = 0.019), and multivariate analysis further confirmed the correlation (adjusted odds ratio [AOR] = 2.41, 1.28-4.56, P = 0.007).

CONCLUSION

Patients with a high-TIL density have a higher major-responder rate than the low-TILs group, indicating patients with a strong immune response benefit more from nCRT. This semi-automatic method can facilitate the individualized preoperative prediction of the TRG for LARC patients before nCRT.

Construction of the Prediction Model for Locally Advanced Rectal Cancer Following Neoadjuvant Chemoradiotherapy Based on Pretreatment Tumor-Infiltrating Macrophage-Associated Biomarkers

Purpose

To assess the value of macrophage-related biomarkers (CD163, CD68, MCSF, and CCL2) for predicting the response to neo-chemoradiotherapy (NCRT) and the prognosis of locally advanced rectal cancer (LARC).

Methods

We enrolled 191 patients who underwent neoadjuvant chemoradiotherapy and radical resection between 2011 and 2015. Tumor tissues were collected before NCRT with a colonoscope and post-surgery and were subjected to immunohistochemical analysis.

Results

The expression levels of macrophage-related biomarkers (CD163, CD68, MCSF, and CCL2) were lower in the pathological complete response (pCR) group when compared with the non-pCR group (all P<0.05). Based on X-tile plots, we divided the tumors in two groups and found that lower pre-NCRT/post-surgical CD163, CD68, MCSF, CCL2 scores correlated with improved DFS. Cox regression analysis demonstrated that pre-NCRT CD163 (HR=1.008, 95% CI 1.003-1.013, P=0.003) and MCSF (HR=2.187, 95% CI 1.343-3.564, P=0.002) scores were independent predictors of DFS. Based on Cox multivariate analysis, we constructed a risk score model with a powerful ability to predict pCR in LARC patients. Moreover, COX regression analysis was performed to explore the role of the risk score in LARC patients. The results demonstrated that tumor size (HR=1.291, P=0.041), worse pathological TNM stage (HR=1.789, P=0.005, and higher risk score (HR=1.084, P<0.001) were significantly associated with impaired disease-free survival. Based on the above results, a nomogram and decision curve analysis were generated.

Conclusion

The expression levels of macrophage-related biomarkers CD163, CD68, MCSF, and CCL2 were associated with chemoradiotherapy resistance and prognosis in LARC patients following NCRT. A risk score model was constructed which could be used to predict LARC outcome.