Prognostic and therapeutic implications of NHERF1 expression and regulation in colorectal cancer

Evolution and current trends in the management of colorectal cancer liver metastasis

Metastatic colorectal cancer (mCRC) is a major cause of cancer-related death, with a 5-year relative overall survival of up to 20%. The liver is the most common site of distant metastasis in colorectal cancer (CRC), with about 50% of CRC patients metastasizing to their liver over the course of their disease. Complete liver resection is the primary modality of treatment for resectable colorectal cancer liver metastasis (CRLM), with an overall 5-year survival rate of up to 58%. However, only 15% to 20% of patients with CRLM are deemed suitable for resection at presentation. For unresectable diseases, the median survival of patients remains low even with the best chemotherapy. In recent decades, the management of CRLM has continued to evolve with the expansion of resection criteria, novel targeted systemic therapies, and improved locoregional therapies. However, due to the heterogeneity of the CRC patient population, the optimal evaluation of treatment options for CRLM remains complex. Therefore, effective management requires a multidisciplinary team to help define resectability and devise a personalized treatment approach, from the initial diagnosis to the final treatment.

GSE1 promotes the proliferation and migration of lung adenocarcinoma cells by downregulating KLF6 expression

Lung cancer is one of the most prevalent human cancers with a high lethality rate worldwide. In this study, we demonstrated that GSE1 (genetic suppressor element 1) expression is aberrantly upregulated in lung adenocarcinoma and that GSE1 depletion inhibits the proliferation and migration of both A549 and H1299 cells. Immunoprecipitation assays demonstrated that GSE1 interacts with histone deacetylase 1 (HDAC1) and other BRAF-HDAC complex (BHC) components in cells. The transcriptome of GSE1-knockdown A549 cells indicated that 207 genes were upregulated and 159 were downregulated based on a p-value < .05 and fold change ≥ 1.5. Bioinformatics analysis suggested that 140 differentially expressed genes harbor binding sites for HDAC1, including the tumor suppressor gene KLF6 (Kruppel-like factor 6). Indeed, quantitative reverse-transcription polymerase chain reaction and western blot analysis revealed that GSE1 could inhibit the transcription of KLF6 in lung cancer cells. In conclusion, GSE1 cooperates with HDAC1 to promote the proliferation and metastasis of non-small cell lung cancer cells through the downregulation of KLF6 expression.

NHERF1/EBP50 immunoexpression in renal cell carcinomas and oncocytomas with ultrastructural analysis of clear cell renal cell carcinoma

Background

Na+/H+ exchanger (NHE) maintains the alkaline pH of epithelial cells working at the cellular membrane and exchanging H+/Na+ ions. In renal tubular epithelial cells, the reabsorption of NaCl is implemented by NHE3 isoform, which is regulated by NHE regulatory factor-1 (NHERF1). Normally situated at the apical zones of proximal tubular cells, NHERF1 participates in cytoskeletal reorganization and signal transduction facilitating structural stability and ion exchange. Based on an extensive search in English literature, NHERF1/EBP50 immunoexpression has been studied in breast, colon, and other tumors with only one study on 21 cases of renal cell carcinomas (RCC).

Methods

Using NHERF1/EBP50 immunohistochemistry (IHC) on 64 (82%) RCCs (34 clear cells, 21 papillary and 9 chromophobe types) and 14 (18%) oncocytomas, we evaluated and scored NHERF1/EBP50 immunoexpression depending on the World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading system followed by ultrastructural identification of microlumen-like structures (MLS) in clear cell renal cell carcinomas (ccRCC).

Results

Staining patterns varied throughout the tumors and within individual tumors. Only ccRCC showed unique MLS within the cytoplasm of tumor cells. All neoplasia-transformed tubular cells, regardless of the tumor grade and stage, had altered immunoexpression of NHERF1/EBP50 ranging from complete absence to aberrant expression in the luminal cell membrane, nuclear or cytoplasmic localizations.

Conclusions

Only ccRCC showed unique dot-like condensations of immunostaining/MLS at membranous, submembranous, and paranuclear localizations. The latter two localizations were mainly observed in the combined WHO/ISUP grade 1 and 2 group compared to the combined group of grade 3 and 4 tumor samples (P=0.0146 and P<0.0001, respectively). Ultrastructurally, the MLS were identified as thick microvilli trapped by a single-layer membrane, displaced into the cytoplasm and ranging from 400 nm to 3.5 µm. These significant ultrastructural reorganizations may contribute to tumor progression, metastasis, and drug resistance.

The diagnostic significance of CDH17-positive circulating tumor cells in patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer deaths in Hong Kong. We tested the hypothesis that circulating tumor cell (CTC) analysis by ARB101 antibody could be used as a tool for CRC detection, progression, and therapy response.

RESEARCH METHODS

ARB101 antibody was used for investigation of CDH17 expression in formalin-fixed, paraffin-embedded (FFPE) tissue sections and circulating tumor cells (CTCs) of CRC patients.

RESULTS

Using ARB101, highest sensitivity was observed in 98/100 (98%) colorectal cancer tissue compared to 72/100 gastric cancer (72%) and 27/32 pancreatic cancer (84%). Immunoreactivity of CDH17 was significantly higher in distant metastatic (tumor-node-metastasis [TNM] stage IV) than non-distant metastatic (TNM stage I to III) CRC. ARB101 antibody also manifested the higher sensitivity than c-erbB2 (8%) and epidermal growth factor receptor (EGFR)-targeting antibodies (37%) with the significance (p < 0.0001). ARB101 positive CTCs were detected in 64/83 (77%) TNM stage I to IV CRC patients. Furthermore, ARB101 positive CTCs detected in TNM stage I to III CRC patients before and after surgical operation are statistically significant (p < 0.0001).

CONCLUSIONS

CTC detection by ARB101 antibody could serve as a potential non-invasive approach for CRC detection, progression, and monitoring of treatment response.

Identification and Validation of Hub Genes for Predicting Treatment Targets and Immune Landscape in Rheumatoid Arthritis

Background

Rheumatoid arthritis (RA) is recognized as a chronic inflammatory disease featured by pathological synovial inflammation. Currently, the underlying pathophysiological mechanisms of RA remain unclear. In the study, we attempted to explore the underlying mechanisms of RA and provide potential targets for the therapy of RA via bioinformatics analysis.

Methods

We downloaded four microarray datasets (GSE77298, GSE55235, GSE12021, and GSE55457) from the GEO database. Firstly, GSE77298 and GSE55457 were identified DEGs by the “limma” and “sva” packages of R software. Then, we performed GO, KEGG, and GSEA enrichment analyses to further analyze the function of DEGs. Hub genes were screened using LASSO analysis and SVM-RFE analysis. To further explore the differences of the expression of hub genes in healthy control and RA patient synovial tissues, we calculated the ROC curves and AUC. The expression levels of hub genes were verified in synovial tissues of normal and RA rats by qRT-PCR and western blot. Furthermore, the CIBERSORTx was implemented to assess the differences of infiltration in 22 immune cells between normal and RA synovial tissues. We explored the association between hub genes and infiltrating immune cells.

Results

CRTAM, CXCL13, and LRRC15 were identified as RA's potential hub genes by machine learning and LASSO algorithms. In addition, we verified the expression levels of three hub genes in the synovial tissue of normal and RA rats by PCR and western blot. Moreover, immune cell infiltration analysis showed that plasma cells, T follicular helper cells, M0 macrophages, M1 macrophages, and gamma delta T cells may be engaged in the development and progression of RA.

Conclusions

In brief, our study identified and validated that three hub genes CRTAM, CXCL13, and LRRC15 might involve in the pathological development of RA, which could provide novel perspectives for the diagnosis and treatment with RA.

Circ_0006174 promotes colorectal cancer progression by sponging microRNA-142-3p and regulating X-linked inhibitor of apoptosis expression

BACKGROUND

Circular RNAs (circRNAs) are crucial in the regulation of gene expression and biological processes. However, in colorectal cancer, the expression characteristics and biological function of circRNA_0006174 (circ_0006174) is not fully understood. This work is aimed to investigate the biological function of circ_0006174 in colorectal cancer and its molecular mechanism.

METHODS

Circ_0006174, microRNA-142-3p and X-linked inhibitor of apoptosis expression levels were detected in colorectal cancer tissues and cells using quantitative real-time polymerase chain reaction analysis or Western blot. The effects of circ_0006174 on colorectal cancer cell proliferation, apoptosis, migration and invasion were detected using the cell counting kit-8 method, bromodeoxyuridine experiments, flow cytometry analysis and Transwell experiments. The targeting relationship among circ_0006174, microRNA-142-3p and X-linked inhibitor of apoptosis was analysed by bioinformatics prediction, dual-luciferase reporter experiment and RNA immunoprecipitation experiment.

RESULTS

Circ_0006174 was up-regulated in colorectal cancer tissues as well as in cell lines, and its high expression was remarkably associated with enlarged tumour volume and advanced tumour, node, metastasis stage of the patients. Circ_0006174 overexpression enhanced colorectal cancer cell proliferation, migration and invasion, and inhibited colorectal cancer cell apoptosis; while knocking down circ_0006174 caused the opposite effects. Circ_0006174 directly targeted and negatively regulated microRNA-142-3p expression, and X-linked inhibitor of apoptosis, a target gene of microRNA-142-3p, could be indirectly and positively modulated by circ_0006174.

CONCLUSION

Circ_0006174 facilitates colorectal cancer cell proliferation, migration and invasion, and represses colorectal cancer cell apoptosis by regulating microRNA-142-3p/X-linked inhibitor of apoptosis axis.

Nuclear expression of NHERF1/EBP50 in Clear Cell Renal Cell Carcinoma

The Na/H exchange regulatory factor 1 or Ezrin-radixin-moesin-binding phosphoprotein 50 (NHERF1/EBP50) is an adaptor protein implicated in the stabilization of molecular complexes linking extracellular signals with the cytoskeleton machinery. NHERF1 expression at the cell cortex is associated with the maintenance of adherent junction integrity in polarized epithelia. The role of NHERF1 in cancer depends on its localization within the cell, acting, in most cases, as a tumor suppressor when localized at the cell membrane, and as an oncogene, when expressed in the cytoplasm or the nucleus of cancer cells. The distribution of NHERF1 in renal cell carcinoma (RCC) has not been yet investigated. In this study, NHERF1 expression was examined by immunohistochemistry in papillary and clear cell RCC. We observed membranous staining in papillary RCC, whereas NHERF1 expression was nuclear and membranous in clear cell RCC. In comparison, NHERF1 immunohistochemistry in clear cell carcinomas of the ovary showed mainly nuclear staining. Our finding of the specific NHERF1 nuclear expression in clear cell carcinomas may help to elucidate the molecular changes that regulate its nuclear accumulation and to better understand its role in this cell compartment.

RPLP1 is highly expressed in hepatocellular carcinoma tissues and promotes proliferation, invasion and migration of human hepatocellular carcinoma Hep3b cells

Hepatocellular carcinoma (HCC) is a common primary malignant tumor with a high mortality rate. Increasing evidence suggests that ribosomal protein LP1 (RPLP1) is involved in the progression of different types of cancer. Thus, the present study aimed to investigate the underlying molecular mechanism of RPLP1 in HCC progression. The cellular behaviors of Hep3b cells were assessed via Cell Counting Kit-8, colony formation, wound healing and Transwell assays. Western blot analysis was performed to detect protein expression levels, while reverse transcription-quantitative PCR analysis was performed to detect mRNA expression levels. The results demonstrated that RPLP1 was highly expressed in HCC tissues and cells, and the overexpression of RPLP1 was associated with a less favorable prognosis of patients with HCC. Notably, downregulation of RPLP1 significantly suppressed the proliferation, migration and invasion of Hep3b cells. Taken together, the results of the present study suggested that RPLP1 acts as an oncogene in HCC, and thus may be used to treat patients with HCC.

Stathmin expression in metastatic colorectal cancer

OBJECTIVES

To evaluate the relationship between stathmin expression and clinical outcome in colorectal cancer (CRC).

BACKGROUND

Stathmin is a phosphoprotein involved in the regulation of microtubule dynamics and integration of intracellular signaling pathways. Stathmin has been implicated in the tumorigenesis of several cancers and is a potential therapeutic target.

METHODS

Stathmin expression was evaluated in 25 metastatic CRC (mCRC) patients by immunohistochemistry (IHC). Ki67 IHC and TUNEL assay were also evaluated in mCRC for cell proliferation and apoptosis.

RESULTS

High expression of stathmin was correlated with CRC metastasis (p = .0084), and significantly worse overall survival (OS) in CRC patients (p = .036). There was a significant increase in cell proliferation and a decrease in apoptosis in liver metastasis compared with CRC primary tumors as determined by Ki67 IHC and TUNEL assay (p < .0001). We also observed a significant positive correlation between stathmin level and cell proliferation in both CRC primary tumor and liver metastasis (p = .0429 to 0.0451; r = .4236 to .4288).

CONCLUSION

Stathmin expression correlated with worse patient prognosis in mCRC patients and positively correlated with increased cell proliferation. Together, our findings indicate stathmin as a novel potential marker for increased risk of CRC-specific mortality and identify stathmin as an attractive therapeutic target for the treatment of mCRC.

Neurensin-2 promotes proliferation, invasion and migration of colorectal cancer cells via interaction with SOX12

Colorectal cancer (CRC) is the third most common malignant type of tumor worldwide. Neurensin-2 (NRSN2) is a small neuronal membrane protein associated with tumorigenesis. Therefore, the present study aimed to investigate the association between NRSN2 and CRC, and further examined the underlying mechanism of its effect on CRC metastasis. Human CRC SW620 cells were used to determine the biological functions of NRSN2 in CRC. Cell counting Kit-8 (CCK8), colony formation, wound-healing and transwell assays were performed to evaluate the role of NRSN2 on survival and metastasis of SW620 cells. The interaction between NRSN2 and SOX12 was determined via bioinformatics analysis and confirmed using immunoprecipitation. It was identified that NRSN2 was highly expressed in CRC cells and served a critical role in CRC cell survival compared with in healthy colon epithelial cells. Furthermore, NRSN2-knockdown inhibited the proliferation, invasion and migration of SW620 cells, while NRSN2 overexpression promoted these cellular processes. Additionally, it was demonstrated that NRSN2 could recruit SOX12 in SW620 cells. NRSN2-knockdown decreased SOX12 expression, while NRSN2 overexpression upregulated SOX12 expression. Overall, the present results suggested NRSN2 as a novel biomarker for CRC diagnosis and identified NRSN2 as a potential therapeutic target for CRC treatment.

Correlation of PRL3 expression with colorectal cancer progression

OBJECTIVES

To evaluate the relationship between phosphatase of regenerating liver 3 (PRL3) expression and clinical outcome in colorectal cancer (CRC).

BACKGROUND

PRL3, a protein tyrosine phosphatase functions as one of the key regulatory enzymes of various signal transduction pathways. PRL3 is highly expressed in a majority of cancers and is a novel potential therapeutic target.

METHODS

PRL3 expression was evaluated by immunohistochemistry in 167 patients with CRC, 37 patients with no disease, and 26 patients with metastatic CRC (mCRC). Phosphorylated Akt at serine 473 (p-Akt S473) expression was also evaluated by immunohistochemistry in mCRC patients.

RESULTS

High expression of PRL3 was correlated with CRC progression, and every one unit increase in PRL3 level contributed to an increase in the rate of death by 1%-1.7%. PRL3 expression was significantly higher in liver metastases compared with primary tumors and showed a significant positive correlation with the expression level of p-Akt S473.

CONCLUSION

PRL3 expression levels associated with CRC progression and metastasis, and positively correlated with activated Akt level in mCRC. Together, these findings indicated that PRL3 might be a potential marker for increased risk of CRC-specific tumor burden and identify PRL3 as an attractive therapeutic target for mCRC treatment.