Expression of ERCC1, RRM1, TUBB3 in correlation with apoptosis repressor ARC, DNA mismatch repair proteins and p53 in liver metastasis of colorectal cancer

Gene network analysis of oxaliplatin-resistant colorectal cancer to target a crucial gene using chitosan/hyaluronic acid/protamine polyplexes containing CRISPR-Cas9

Colorectal cancer (CRC) treatment is dramatically hampered by resistance to oxaliplatin alone or in the combination of irinotecan or 5-fluorouracil and leucovorin. This study aims to design and assess Chitosan/Hyaluronic Acid/Protamine sulfate (CS/HA/PS) polyplexes loaded with CRISPR plasmid for targeting a key gene in cancer drug resistance. Here, recent findings were considered to validate oxaliplatin-resistant CRC-related genes and systems biology approaches employed to detect the critical gene. The polyplexes were characterized according to particle size, zeta potential, and stability. Moreover, carrier toxicity and transfection efficiency were assessed on oxaliplatin-resistant HT-29 cells. The post-transfection evaluations were performed to confirm gene disruption-mediated CRISPR. Eventually, excision cross complementation group 1(ERCC1), a crucial member of the nucleotide excision repair pathway, was selected to be targeted using CRISPR/Cas9 to reverse oxaliplatin resistance in HT-29 cells. CS/HA/PS polyplexes containing CRISPR/Cas9 plasmid exhibited negligible toxicity and comparable transfection efficiency with Lipofectamine™. Following the efficient gene delivery, sequences in CRISPR/Cas9 target sites were altered, ERCC1 was downregulated, and drug sensitivity was successfully restored in oxaliplatin-resistant cells. Findings indicate that CS/HA/PS/CRISPR polyplexes provide a potential strategy for delivering cargo and targeting oxaliplatin resistance-related gene to manipulate drug resistance as a rising concern in cancer therapeutic approaches.

Intracellular and extracellular factors of colorectal cancer liver metastasis: a pivotal perplex to be fully elucidated

Metastasis is the leading cause of death in colorectal cancer (CRC) patients, and the liver is the most common site of metastasis. Tumor cell metastasis can be thought of as an invasion-metastasis cascade and metastatic organotropism is thought to be a process that relies on the intrinsic properties of tumor cells and their interactions with molecules and cells in the microenvironment. Many studies have provided new insights into the molecular mechanism and contributing factors involved in CRC liver metastasis for a better understanding of the organ-specific metastasis process. The purpose of this review is to summarize the theories that explain CRC liver metastasis at multiple molecular dimensions (including genetic and non-genetic factors), as well as the main factors that cause CRC liver metastasis. Many findings suggest that metastasis may occur earlier than expected and with specific organ-anchoring property. The emergence of potential metastatic clones, the timing of dissemination, and the distinct routes of metastasis have been explained by genomic studies. The main force of CRC liver metastasis is also thought to be epigenetic alterations and dynamic phenotypic traits. Furthermore, we review key extrinsic factors that influence CRC cell metastasis and liver tropisms, such as pre-niches, tumor stromal cells, adhesion molecules, and immune/inflammatory responses in the tumor microenvironment. In addition, biomarkers associated with early diagnosis, prognosis, and recurrence of liver metastasis from CRC are summarized to enlighten potential clinical practice, including some markers that can be used as therapeutic targets to provide new perspectives for the treatment strategies of CRC liver metastasis.

Expression of apoptosis repressor with caspase recruitment domain (ARC) in familial adenomatous polyposis (FAP) adenomas and its correlation with DNA mismatch repair proteins, p53, Bcl-2, COX-2 and beta-catenin

Background

Colorectal familial adenomatous polyposis (FAP) adenomas exhibit a uniform pathogenetic basis caused by a germline mutation in the adenomatous polyposis gene (APC), but the molecular changes leading to their development are incompletely understood. However, dysregulated apoptosis is known to substantially affect the development of colonic adenomas. One of the key regulatory proteins involved in apoptosis is apoptosis repressor with caspase recruitment domain (ARC).

Methods

The expression of nuclear and cytoplasmic ARC in 212 adenomas from 80 patients was analyzed by immunohistochemistry. We also compared expression levels of ARC with the expression levels of p53, Bcl-2, COX-2, and MMR proteins. Statistical analyses were performed by Spearman’s rank correlation and linear regression test.

Results

ARC was overexpressed in the nuclei and cytoplasm of most FAP adenomas investigated. Cytoplasmic ARC staining was moderately stronger (score 2) in 49.1% (n = 104/212) and substantially stronger (score 3) in 32.5% (n = 69/212) of adenomas compared to non-tumorous colorectal mucosa. In 18.4% (n = 39/212) of adenomas, cytoplasmic ARC staining was equivalent to that in non-tumorous mucosa.

Nuclear expression of ARC in over 75% of cells was present in 30.7% (n = 65/212) of investigated adenomas, and nuclear expression in 10–75% of cells was detected in 62.7% (n = 133/212). ARC expression in under 10% of nuclei was found in 6.6% (n = 14/212) of adenomas.

The correlation between nuclear ARC expression and cytoplasmic ARC expression was highly significant (p = 0.001). Moreover, nuclear ARC expression correlated positively with overexpression of Bcl-2, COX-2 p53 and β-catenin. Cytoplasmic ARC also correlated with overexpression of Bcl-2. Sporadic MMR deficiency was detected in very few FAP adenomas and showed no correlation with nuclear or cytoplasmic ARC.

Conclusions

Our results demonstrated that both cytoplasmic and nuclear ARC are overexpressed in FAP adenomas, thus in a homogenous collective. The highly significant correlation between nuclear ARC and nuclear β-catenin suggested that ARC might be regulated by β-catenin in FAP adenomas. Because of its further correlations with p53, Bcl-2, and COX-2, nuclear ARC might play a substantial role not only in carcinomas but also in precursor lesions.

High-grade serous peritoneal cancer follows a high stromal response signature and shows worse outcome than ovarian cancer

In the era of personalized medicine, where transition from organ‐based to individualized genetic diagnosis takes place, the tailoring of treatment in cancer becomes increasingly important. This is particularly true for high‐grade, advanced FIGO stage serous adenocarcinomas of the ovary (OC), fallopian tube (TC), and peritoneum (PC), which are currently all treated identically. We analyzed three independent patient cohorts using histopathologically classified diagnosis and various molecular approaches (transcriptomics, immunohistochemistry, next‐generation sequencing, fluorescent and chromogenic in situ hybridization). Using multivariate Cox regression model, we found that PC is more aggressive compared with advanced‐stage OC independent of residual disease as shown by an earlier relapse‐free survival in two large cohorts (HR: 2.63, CI: 1.59–4.37, P < 0.001, and HR: 1.66, CI: 1.04–2.63, P < 0.033). In line with these findings, transcriptomic data revealed differentially expressed gene signatures identifying PC as high stromal response tumors. The third independent cohort (n = 4054) showed a distinction between these cancer types for markers suggested to be predictive for chemotherapy drug response. Our findings add additional evidence that ovarian and peritoneal cancers are epidemiologically and molecularly distinct diseases. Moreover, our data also suggest consideration of the tumor‐sampling site for future diagnosis and treatment decisions.

LINC02535 co-functions with PCBP2 to regulate DNA damage repair in cervical cancer by stabilizing RRM1 mRNA

Cervical cancer (CC) is one of the commonest malignant cancers among women with high morbidity and mortality. Despite encouraging advances had been found in diagnostic and therapeutic strategies, effective therapeutic strategy and further exploration of the mechanism underlying in CC is still needed. We searched The Cancer Genome Atlas database and found that long noncoding RNA LINC02535 was highly expressed in CC. LINC02535 has not been studied in CC, and its molecular regulation mechanism remains unknown. Based on starBase database, LINC02535 could potentially bind poly (rC) binding protein 2 (PCBP2). In the present study, we discovered a significant increase of the LINC02535 and PCBP2 expression in CC tissues and cells as compared with the adjacent normal tissues and normal cervical epithelial cells. LINC02535 and PCBP2 can bind with each other and were colocated in cytoplasm. LINC02535 and PCBP2 promoted cell proliferation, migration, invasion, and suppressed apoptosis in CC. LINC02535 and PCBP2 facilitated the repair of DNA damage to promote CC progression. LINC02535 cooperated with PCBP2 to enhance the stability of RRM1 messenger RNA (mRNA). RRM1 promoted the repair of DNA damage and epithelial-to-mesenchymal transition (EMT) process in CC cells. LINC02535 regulated tumorigenesis in vivo. In conclusion, LINC02535 cooperated with PCBP2, regulated stability of RRM1 mRNA to promote cell proliferation and EMT process in CC cells by facilitating the repair of DNA damage, providing a potential biomarker for CC.

WGS-based telomere length analysis in Dutch family trios implicates stronger maternal inheritance and a role for RRM1 gene

Telomere length (TL) regulation is an important factor in ageing, reproduction and cancer development. Genetic, hereditary and environmental factors regulating TL are currently widely investigated, however, their relative contribution to TL variability is still understudied. We have used whole genome sequencing data of 250 family trios from the Genome of the Netherlands project to perform computational measurement of TL and a series of regression and genome-wide association analyses to reveal TL inheritance patterns and associated genetic factors. Our results confirm that TL is a largely heritable trait, primarily with mother's, and, to a lesser extent, with father's TL having the strongest influence on the offspring. In this cohort, mother's, but not father's age at conception was positively linked to offspring TL. Age-related TL attrition of 40 bp/year had relatively small influence on TL variability. Finally, we have identified TL-associated variations in ribonuclease reductase catalytic subunit M1 (RRM1 gene), which is known to regulate telomere maintenance in yeast. We also highlight the importance of multivariate approach and the limitations of existing tools for the analysis of TL as a polygenic heritable quantitative trait.

Five Core Genes Related to the Progression and Prognosis of Hepatocellular Carcinoma Identified by Analysis of a Coexpression Network

The molecular mechanism of tumorigenesis of the prevalent cancer hepatocellular carcinoma (HCC) is unclear. In this study, through weighted gene coexpression network analysis, a coexpression network was constructed by selecting the top 25% most variant genes in the dataset GSE62232. The average linkage hierarchical clustering identified 24 modules, and among them, the pink module associated with prognosis of HCC was screened. Five gene candidates (PCNA, RFC4, PTTG1, H2AFZ, and RRM1) with a common network in the module were screened after the protein-protein interaction network complex was combined with the coexpression network. After progression and survival analysis, all candidates were identified as real core genes. According to the Human Protein Atlas and the Oncomine database, these genes were dysregulated in HCC samples. The receiver operating characteristic curve proved that the expression levels of the core genes had high diagnostic efficacy. The results of gene set enrichment analysis and functional enrichment analysis demonstrated the importance of the cell cycle-related pathways in HCC progression and prognosis. In conclusion, the five real core genes and cell cycle-related pathways identified in this study could greatly improve the knowledge about HCC progression and contribute to HCC treatment.

Cathelicidin Suppresses Colon Cancer Metastasis via a P2RX7-Dependent Mechanism

The antimicrobial peptide cathelicidin inhibits development of colitis-associated colon cancer. However, the role of cathelicidin in colon cancer metastasis remains unknown. We hypothesized that cathelicidin is effective in inhibiting colon cancer metastasis. Human colon cancer HT-29 cells were injected intravenously into nude mice. Control HA-tagged adeno-associated virus (HA-AAV) or cathelicidin-overexpressing AAV (CAMP-HA-AAV) were injected intravenously into nude mice on the same day. Four weeks later, the nude mice were assessed for lung and liver metastases. Human colon cancer SW620 cells were used to study the effect of cathelicidin on cell migration and cytoskeleton. Incubation of SW620 cells with cathelicidin dose-dependently reduced cell migration, disrupted cytoskeletal structure, and reduced βIII-tubulin (TUBB3) mRNA expression. The addition of the P2RX7 antagonist KN62, but not the FPRL1 antagonist WRW4, prevented the LL-37-mediated inhibition of cell migration and TUBB3 mRNA expression. The CAMP-HA-AAV-overexpressing group showed significantly reduced human CK20 protein (by 60%) and TUBB3 mRNA expression (by 40%) in the lungs and liver of the HT-29-loaded nude mice, compared to the HA-AAV control group. Intraperitoneal injection of KN62 reversed the CAMP-HA-AAV-mediated inhibition of human CK20 and TUBB3 expression in the lungs and liver of HT-29-loaded nude mice. In conclusion, cathelicidin inhibits colon cancer metastasis via a P2RX7-dependent pathway.

Molecular and Immunohistochemical Markers with Prognostic and Predictive Significance in Liver Metastases from Colorectal Carcinoma

Despite the significant recent achievements in the diagnosis and treatment of colorectal cancer (CRC), the prognosis of these patients has currently plateaued. During the past few years, the opportunity to consider multiple treatment modalities (including surgery and other locoregional treatments, systemic therapy, and targeted therapy) led to the research of novel prognostic and predictive biomarkers in CRC liver metastases (CRCLM) patients. In this review, we seek to describe the current state of knowledge of CRCLM biomarkers and to outline impending clinical perspectives, in particular focusing on the cutting-edge tools available for their characterization.