CPXM1 correlates to poor prognosis and immune cell infiltration in gastric cancer.

Background: Gastric cancer (GC) is the fourth most common cause of cancer-related death and the fifth most frequent malignant cancer, especially advanced GC. Carboxypeptidase X member 1 (CPXM1) is an epigenetic factor involved in many physiological processes, including osteoclast differentiation and adipogenesis. Several studies have shown the association of CPXM1 with multiple tumors; however, the mechanism of CPXM1 involvement in the progression of GC is yet to be characterized. Method: CPXM1 expression data were obtained from the Tumor Immune Estimation Resource. The Cancer Genome Atlas and the Gene Expression Omnibus databases were used to obtain patient-matched clinicopathological information, and the Kaplan-Meier plot database was utilized for the prognosis analysis of GC patients. The Catalog of Somatic Mutations in Cancer and cBioportal databases were adopted to study CPXM1 mutations in tumors. Next, we utilized the Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and Gene Set Enrichment Analysis for mechanism research. Furthermore, we performed tumor microenvironment and immune infiltration analysis based on CPXM1. Finally, we predicted sensitivity to several targeted drugs in GC patients based on CPXM1.CPXM1 is upregulated in GC and is correlated with poor prognosis, gender, and tumor stage in GC patients. Gene enrichment analysis suggested that CPXM1 may regulate the occurrence and progression of GC via the PI3K-AKT and TGF-ß pathway. Moreover, CPXM1 expression results in an increase in the proportion of immune and stromal cells. Additionally, the proportion of plasma cells was inversely related to the expression of CPXM1, whereas macrophage M2 expression was proportionate to CPXM1 expression. Finally, six small-molecule drugs that showed notable variations in IC50 between two groups were screened. Conclusion: These results suggested that CPXM1 regulates the progression of GC and may represent a novel target for the detection and treatment of GC.

Apolipoprotein C1 promotes tumor progression in gastric cancer.

Background: Gastric cancer (GC) is a malignancy with the worst prognosis that seriously threatens human health, especially in East Asia. Apolipoprotein C1 (apoc1) belongs to the apolipoprotein family. In addition, apoc1 has been associated with various tumors. However, its role in GC remains unclear. Methods: Firstly, we quantified its expression in GC and adjacent tumor tissues, using The Cancer Genome Atlas (TCGA). Next, we assessed cell invasion and migration abilities. Finally, we revealed the role of apoc1 in the tumor microenvironment (TME), immune cell infiltration and drug sensitivity. Results: Firstly, in TCGA database, it has been shown that elevated expression of apoc1 was identified in various cancers, including GC, then we found that high expression of apoc1 was significantly correlated with poor prognosis in GC. Histologically, apoc1 expression is proportional to grade, cancer stage, and T stage. The experimental results showed that apoc1 promoted cell invasion and migration. Then GO, KEGG, and GSEA pathway analyses indicated that apoc1 may be involved in the WNT pathway and immune regulation. Furthermore, we found out the tumor-infiltrating immune cells related to apoc1 in the tumor microenvironment (TME) using TIMER. Finally, we investigated the correlation between apoc1 expression and drug sensitivity, PD-1 and CTLA-4 therapy. Conclusions: These results suggest that apoc1 participates in the evolution of GC, and may represent a potential target for detection and immunotherapy in GC.

Laparoscopic single-layer running "trapezoid-shaped" suture versus mechanical stapling for esophagojejunostomy after total gastrectomy for gastric cancer: cost-effect analysis of propensity score-matched study cohorts.

OBJECTIVES: Totally laparoscopic total gastrectomy has been developed with difficulty in intracorporeal esophagojejunostomy. Although mechanical stapling has been widely used for intracorporeal esophagojejunostomy, manual suture holds great promise with the emergence of high-resolution 3D vision and robotic surgery. After exploration of how to improve the safety and efficiency of intracorporeal suture for esophagojejunostomy, we recommended the technique of single-layer running "trapezoid-shaped" suture. The cost-effectiveness was analyzed by comparing with conventional mechanical stapling. METHODS: The study retrospectively reviewed the patients undergoing laparoscopic gastrectomy for gastric cancer from January 2010 to December 2021. The patients were divided into two cohorts based on the methods of intracorporeal esophagojejunostomy: manual suture versus stapling suture. Propensity score matching was performed to match patients from the two cohorts at a ratio of 1:1. Then group comparison was made to determine whether manual suture was non-inferior to stapling suture in terms of operation time, anastomotic complications, postoperative hospital stay, and surgical cost. RESULTS: The study included 582 patients with laparoscopic total gastrectomy. The manual and stapling suture for esophagojejunostomy were performed in 50 and 532 patients, respectively. In manual suture cohort, the median time for the whole operation and digestive tract reconstruction were 300 min and 110 min. There was no anastomotic bleeding and stenosis but two cases of anastomotic leak which occurred at 3 days after surgery. The median length of postoperative hospital stay was 11 days. After propensity score matching, group comparison yielded two variables with statistical significance: time for digestive tract reconstruction and surgery cost. The manual suture cohort spent less money but more time for esophagojejunostomy. Intriguingly, the learning curve of manual suture revealed that the time for digestive tract reconstruction was declined with accumulated number of operations. CONCLUSIONS: Laparoscopic single-layer running "trapezoid-shaped" suture appears safe and cost-effective for intracorporeal esophagojejunostomy after total gastrectomy. Although the concern remains about prolonged operation time for beginners of performing the suture method, adequate practice is expected to shorten the operation time based on our learning curve analysis.

Cetuximab functionalization strategy for combining active targeting and antimigration capacities of a hybrid composite nanoplatform applied to deliver 5-fluorouracil: toward colorectal cancer treatment.

Antibody-functionalized targeted nanocarriers to deliver chemotherapeutics have been widely explored. However, it remains highly desirable to understand and apply the antitumor potential of antibodies integrated in hybrid composite nanoplatforms. Herein, mesoporous silica nanoparticles, a supported lipid bilayer and cetuximab were integrated to fabricate a hybrid nanoplatform for effectively encapsulating and selectively delivering 5-fluorouracil (5-FU) against colorectal cancer (CRC) cells. The specially designed nanoplatform exhibited superior properties, such as satisfying size distribution, dispersity and stability, drug encapsulation, controlled release, and cellular uptake. Interestingly, the modification of cetuximab onto nanoplatforms without drug loading can significantly inhibit the migration and invasion of CRC cells through suppressing the epidermal growth factor receptor (EGFR)-associated signaling pathway. Furthermore, delivery of 5-FU by using this nanoplatform can remarkably induce cytotoxicity, cell cycle arrest, and cell apoptosis for CRC cells with high EGFR expression. Overall, this nanostructured platform can dramatically improve the tumor killing effects of encapsulated chemotherapeutics and present antimigration effects derived from the antibody modified on it. Moreover, in vivo biodistribution experiments demonstrated the superior tumor targeting ability of the targeted nanoparticles. Thus, this targeted nanoplatform has substantial potential in combinational therapy of antibodies and chemotherapy agents against colorectal cancer.

TCONS_00012883 promotes proliferation and metastasis via DDX3/YY1/MMP1/PI3K-AKT axis in colorectal cancer.

BACKGROUND: Long noncoding RNAs (lncRNAs) have emerged as key regulators in multiple cancers, including colorectal cancer (CRC). However, the biological functions and molecular mechanisms underlying most lncRNAs in CRC remain largely unknown. METHODS: A novel lncRNA (TCONS_00012883) was identified using RNA sequencing. The level of TCONS_00012883 expression in CRC was analyzed by qRT-PCR. The biological functions of TCONS_00012883 in CRC were investigated by a series of in vitro and in vivo experiments: CCK8, colony formation, EdU, flow cytometric assays, transwell assays, and mouse xenograft. The molecular mechanisms of TCONS_00012883 were demonstrated by RNA pulldown, mass spectrometry analysis, RIP, coimmunoprecipitation, RNA sequencing, chromatin immunoprecipitation, and rescue experiments. RESULTS: Elevated expression of TCONS_00012883 was confirmed in CRC and positively associated with a poor prognosis. Functionally, gain- and loss-of-function assays indicated that TCONS_00012883 promoted proliferation and metastasis of CRC cell lines in vitro and in vivo. Mechanistically, RNA pulldown and mass spectrometry analysis showed that DEAD-box helicase 3 (DDX3) was the protein partner of TCONS_00012883. Furthermore, RNA sequencing assay revealed that matrix metallopeptidase 1 (MMP1) was the downstream of TCONS_00012883. Intriguingly, we found that transcription factor (YY1) could serve as a bridge between TCONS_00012883, DDX3, and MMP1. CONCLUSIONS: TCONS_00012883 significantly promoted CRC progression via the DDX3/YY1/MMP1 axis, and thus, may act as a major role in diagnosis and therapy of CRC.

MicroRNA-1224-5p Inhibits Metastasis and Epithelial-Mesenchymal Transition in Colorectal Cancer by Targeting SP1-Mediated NF-κB Signaling Pathways.

MicroRNAs (miRNAs) are small non-coding RNAs that play pivotal roles in cancer initiation and progression. However, the roles and molecular mechanisms of miRNAs in colorectal cancer (CRC) progression remain unclear. Here, we show that downregulation of miR-1224-5p in CRC is negatively correlated with SP1 expression and metastasis in patients and xenografted mouse models. Gain- and loss-of-function assays reveal that miR-1224-5p suppresses the migration, invasion, and epithelial-mesenchymal transition (EMT) of CRC cells in vitro and in vivo by directly targeting SP1. Moreover, SP1 promotes the phosphorylation of p65, which results in EMT progress in CRC cells. Clinical analysis reveals that miR-1224-5p and SP1 expression are remarkably associated with advanced clinical features and unfavorable prognosis of patients with CRC. Further study confirms that hypoxia accounts for the depletion of miR-1224-5p in CRC. The enhancement of hypoxia during epithelial-mesenchymal transition and metastasis of CRC cells is abolished by miR-1224-5p. Our findings provide the first evidence that miR-1224-5p is a potential therapeutic target and prognostic biomarker for patients with CRC.

RFC2, a direct target of miR-744, modulates the cell cycle and promotes the proliferation of CRC cells.

Colorectal cancer (CRC) is a common digestive tract malignancy, which is characterized by high mortality, morbidity, and poor prognosis. Replication factor C subunit 2 (RFC2), one RFC family member, was reported to be related to various malignancies and plays an important role in proliferation, invasion, and metastasis. Nonetheless, the RFC2 biological role within CRC is still unknown. RFC2 expression profiles in CRC tissues were collected based on The Cancer Genome Atlas database, whereas miR-744 and RFC2 expression levels were detected in human CRC tissues. miR-744 and RFC2 effects on the proliferation of CRC were assessed both in vivo and in vitro. RFC2 was recognized to be a direct miR-744 target through luciferase reporter assay. RFC2 upregulation was observed within CRC tissues, and a high RFC2 level showed a correlation with poor clinicopathological symptoms. RFC2 knockdown inhibited CRC cell proliferation through promoting cell cycle arrest at the G1 phase, which was achieved by cyclin E2 (CCNE2) downregulation in vivo and in vitro. miR-744 was identified to be the tumor suppressor microRNA, which targeted RFC2 directly for inhibiting the proliferation of CRC cells both in vivo and in vitro. miR-744 downregulation was detected within CRC tissue, and messenger RNA expression showed a negative correlation with RFC2 expression within CRC tissues. Our study demonstrates that the miR-744/RFC2/CCNE2 axis potentially provides a candidate for a treatment strategy for CRC.

NMI promotes cell proliferation through TGFß/Smad pathway by upregulating STAT1 in colorectal cancer.

Colorectal cancer (CRC) is still a fatal health problem around the world. The underlying mechanisms of CRC have not been fully elucidated. N-myc interactor (NMI) acts as an oncogene or a tumor-suppressor gene in several kinds of cancers but CRC. Here, the expression of NMI was found higher in CRC tissues and cells. Higher expression of NMI indicated the poorer prognosis of CRC patients. Moreover, the proliferation of CRC cells was suppressed significantly after we silenced the expression of NMI, while overexpression of NMI promoted CRC cell proliferation. Flow cytometry demonstrated that NMI promoted cell proliferation through facilitating cell transition from the G1 phase to the S phase. Furthermore, it was found that NMI suppressed the phosphorylation of Smad3 by upregulating the expression of STAT1. The effect of NMI depletion on cell proliferation could be reversed by using Smad3 inhibitor SIS3. In summary, our findings demonstrated that NMI promoted cell proliferation via TGFß/Smad pathway and could indicate the prognosis of patients with CRC.

Upregulated METTL3 promotes metastasis of colorectal Cancer via miR-1246/SPRED2/MAPK signaling pathway.

BACKGROUND: m6A modification has been proved to play an important role in many biological processes. METTL3 as the main methyltransferase for methylation process has been found to be upregulated in many cancers, including CRC. Here, we investigate m6A modification and the underlying mechanism of METTL3 in the development of CRC. METHODS: The expression of METTL3 was detected in large clinical patient samples. To evaluate the function of METTL3 in vitro and in vivo, colony formation, CCK-8, cell migration and invasion assays were performed. To find out the downstream target of METTL3, GEO dataset was re-mined. We analyzed expression and metastasis-related miRNA by Pearson correlation, and miR-1246 was selected. Here, to identify the downstream target of miR-1246, Targetscan and miRWalk were used. RIP and luciferase reporter assay further confirmed SPRED2 as the direct target of miR-1246. RESULTS: We found that upregulated METTL3 is responsible for abnormal m6A modification in CRC and correlates positively with tumor metastasis. The gain- and loss-of-function indicates that METTL3 promotes cell migration and invasion in vitro and in vivo. Additionally, we confirmed that METTL3 can methylate pri-miR-1246, which further promotes the maturation of pri-miR-1246. By using bioinformatics tools, anti-oncogene SPRED2 was identified as the downstream target of miR-1246, wherein downregulated SPRED2 further reverses the inhibition of the MAPK pathway. CONCLUSIONS: The present study demonstrates that the METTL3/miR-1246/SPRED2 axis plays an important role in tumor metastasis and provides a new m6A modification pattern in CRC development.

The Diverse Oncogenic and Tumor Suppressor Roles of microRNA-105 in Cancer.

MicroRNAs (miRNAs) are non-coding small RNA molecules that regulate gene expression at the post-transcriptional/translational level. They act a considerable role not only in the normal progress of development but also in aberrant human diseases, including malignancy. With accumulating proofs of miR-105, the complex role of miR-105 during cancer initiation and progression is gradually emerging. miR-105 acts as a tumor suppressor by inhibiting tumor growth and metastasis or as an oncogene by promoting tumor initiation and invasion, depending on particular tumor contexts and base-pairing genes. In this review, we emphasize the characteristics of miR-105 in cancer to elucidate various deadly tumors and discuss transcriptional regulations that may explain fluctuations in miR-105 expression. This review may provide new ideas for applying miR-105 as a diagnostic and prognostic biomarker.

CDCA2 promotes the proliferation of colorectal cancer cells by activating the AKT/CCND1 pathway in vitro and in vivo.

BACKGROUND: Cell division cycle associated 2 (CDCA2), upregulated in lung adenocarcinoma and oral squamous cell carcinoma, may be related to some malignant diseases. Nevertheless, its role in colorectal cancer (CRC) remains unknown. METHODS: CDCA2 expression was analyzed using The Cancer Genome Atlas (TCGA), quantitative real-time PCR (qRT-PCR), and immunohistochemistry. The impact of CDCA2 on cell proliferation was analyzed via loss- or gain-of-function assays. Furthermore, gene set enrichment analysis was conducted to explore the potential mechanism of CDCA2 in CRC. Lastly, the expression levels of CCND1 and AKT were measured in CRC cell lines. RESULTS: Our study revealed that CDCA2 expression was associated with tumor progression. Through loss- or gain-of-function assays, we found that upregulation of CDCA2 promoted the proliferation of DLD-1 cells, however, downregulation of CDCA2 in SW480 cells restrained proliferative capacity both in vitro and in vivo. The results of flow cytometry showed that CDCA2 promoted cell cycle progression via upregulation of CCND1 in CRC cell lines. In the following experiments, we found that CDCA2 regulated CCND1 expression through activating the PI3K/AKT pathway, and confirmed this using a specific PI3K inhibitor (LY294002). CONCLUSIONS: This study demonstrates that overexpression of CDCA2 might target CCND1 to promote CRC cell proliferation and tumorigenesis through activation of the PI3K/AKT pathway.

Long noncoding RNA Linc02023 regulates PTEN stability and suppresses tumorigenesis of colorectal cancer in a PTEN-dependent pathway.

Phosphatase and tensin homolog (PTEN), one of the most frequently mutated tumor suppressor genes in human cancer, is pivotal in the progression of colorectal cancer. Therefore, the regulation of PTEN has emerged as a theme of intense research in tumor biology. This study aims to show that long noncoding RNA (lncRNA) Linc02023 aberrant downregulation in colorectal cancer correlates positively with the expression of PTEN and CDKN2B but negatively with the tumor size in patients and xenografted mouse models. The gain- and loss-of-function investigation reveals that Linc02023 suppresses the proliferation of colorectal cancer cells in vitro and in vivo with apoptosis promotion and cell cycle rearrangement. Mechanistically, Linc02023 specifically binds to PTEN and blocks its interaction with and ubiquitination by WWP2, stabilizing it and suppressing its downstream expression. In conclusion, this study demonstrates that lncRNA Linc02023 may serve as a novel therapeutic target by restoring the PTEN tumor suppressor activity.

Construction of ceRNA networks reveals differences between distal and proximal colon cancers.

Although colon cancer is often referred to as a homogeneous entity, an increasing number of studies have revealed that colon cancer can be divided according to the anatomic site of the cancer. However, few studies have reported the difference between distal and proximal colon cancer with regard to molecular mechanism, and especially non­coding RNA molecules. In the present study, the data of 186 colon tumour tissues and 17 adjacent non­tumour colon tissues in the left colon and 229 colon tumour tissues and 21 adjacent non­tumour colon tissues in the right colon were obtained from The Cancer Genome Atlas (TCGA). A total of 879 lncRNAs, 165 miRNAs and 2,028 mRNAs were identified as left­specific RNAs [log2(fold change)>2, FDR<0.01]. There were 916 lncRNAs, 227 miRNAs and 2,069 mRNAs identified in right colon cancer. The Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways were analysed for 2,028 mRNAs from left colon cancer and 2,069 mRNAs from right colon cancer. After removing the elements of the intersection from side­specific lncRNAs of the left and right, we identified specific lncRNAs included exclusively in left or right colon cancer, including 277 lncRNAs in left colon cancer and 314 lncRNAs in right colon cancer. Among these lncRNAs, 20 lncRNAs from the left and 25 lncRNAs from the right were revealed to be associated with overall survival. Then, ceRNA networks were constructed. There were 18 lncRNAs, 22 miRNAs and 57 mRNAs included in the left colon cancer ceRNA network and 21 lncRNAs, 27 miRNAs and 55 mRNAs included in the right ceRNA network. In total, 15 lncRNAs were revealed to be significantly related to clinical features, two of which were ascertained by testing the mRNA expression of tissues. In conclusion, our research aimed to detect the difference between colon cancer in the left and the right colon and to assist in the identification of new potential biomarkers to be used for diagnostic and prognostic purposes.

CDCA3 mediates p21-dependent proliferation by regulating E2F1 expression in colorectal cancer.

Dysregulated cell cycle progression serves a crucial role in tumor development. Cell division cycle-associated 3 (CDCA3) is considered a trigger of mitotic entry; it is an important part of the S phase kinase-associated protein 1/Cullin/F-box ubiquitin ligase complex and mediates the destruction of mitosis-inhibitory kinase wee1. However, little is known about the role of CDCA3 in cancer, particularly colorectal cancer (CRC). The present study aimed to explore the biological and clinical significance of CDCA3 in CRC growth and progression. CDCA3 expression was significantly associated with tumor progression and poor survival. Overexpression of CDCA3 increased proliferation in LoVo CRC cells, whereas CDCA3 knockdown in SW480 CRC cells led to decreased proliferation, in vitro and in vivo. Further mechanistic investigations demonstrated that reduced CDCA3 expression resulted in G1/S phase transition arrest, which was attributed to a significant accumulation of p21 in SW480 cells; conversely, increased CDCA3 expression promoted G1/S phase transition through decreased p21 accumulation in LoVo cells. It was also demonstrated that CDCA3 was able to regulate the expression of transcription factor E2F1, thereby repressing p21 expression. Taken together, these results suggested that overexpression of CDCA3 may serve a crucial role in tumor malignant potential and that CDCA3 may be used as a prognostic factor and a potential therapeutic target in CRC.