Survival outcome of local vs. radical excision in rectal gastrointestinal stromal tumor: a SEER database analysis.

BACKGROUND: The choice of surgical strategy for patients with rectal gastrointestinal stromal tumor (GIST) remains controversial. This study aims to address whether the surgical procedure [local excision (LE) vs. radical excision (RE)] influences the survival outcomes. METHODS: The information of the patients recruited in this study was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. A survival curve was used to evaluate the differences in cancer-specific survival (CSS). RESULTS: No significant difference was detected in the CSS between the LE and RE groups. Also, no significant differences were observed in the CSS between the two groups with respect to different T classification, N classification, tumor differentiation, tumor size, regional LN surgery, age, gender, race, chemotherapy, and radiotherapy. The T classification and age were independent prognostic factors in rectal GIST patients. CONCLUSIONS: LE and RE have similar survival time after surgery, and LE could be considered as an effective surgical approach for rectal GIST.

A survival comparison of gastric mucin-producing adenocarcinoma to conventional adenocarcinoma: a SEER database analysis.

BACKGROUND: Compared to conventional adenocarcinoma (CA), mucin-producing adenocarcinoma (MPA) is an uncommon histological subtype and is usually separated from other histological types and has been evaluated separately. The objective was to compare the clinicopathological characteristics and survivals of MPA with CA. METHODS: We retrospectively analyzed 1515 MPA patients in SEER database. Log-rank tests and KM survival curves were applied to determine the differences in overall survival (OS) and cancer specific survival (CSS) time. RESULTS: No significant differences were noted in OS and CSS time. The MPA patients who were treated with surgery and chemotherapy exhibited longer OS and CSS time periods than those without treatment. MPA patients treated with radiotherapy exhibited similar OS and CSS time with those without radiotherapy. MPA was not a prognostic factor of survival. CONCLUSIONS: MPA was a rare histological type of gastric cancer. Patients with MPA exhibited similar prognosis with those with CA. Surgery and chemotherapy were effective treatments for patients with MPA.

Proximal versus total gastrectomy for proximal gastric cancer: a Surveillance, Epidemiology, and End Results Program database analysis.

Aims: To addresses whether surgical procedure (proximal gastrectomy [PG] vs total gastrectomy [TG]) influences survival outcomes. Methods: Patients were selected from Surveillance, Epidemiology and End Results Program (SEER) database. Survival curve was used to evaluate the differences in overall survival (OS) and cancer-specific survival (CSS). Results: No significant difference was detected in OS and CSS time between PG and TG groups. Also, no significant differences were observed in OS and CSS times between the two groups with respect to clinical stage, tumor stage, node stage, age, gender and tumor differentiation. Tumor differentiation, tumor size, tumor stage, node stage and age were independent prognostic factors in patients with proximal gastric cancer. Conclusions: TG was not necessary for proximal gastric cancer patients, and PG may be considered as an ideal surgery approach.

Genome-scale CRISPR-Cas9 knockout screening in gastrointestinal stromal tumor with Imatinib resistance.

Genome-scale CRISPR-Cas9 Knockout Screening was applied to investigate novel targets in imatinib-resistant gastrointestinal stromal tumor (GIST). 20 genes and 2 miRNAs have been selected by total reads of sgRNA and sgRNA diversity, which has been further validated in imatinib-resistant GIST cells by CCK8 and qPCR analysis. Our study has finally revealed 9 genes (DBP, NR3C1, TCF12, TP53, ZNF12, SOCS6, ZFP36, ACYP1, and DRD1) involved in imatinib-resistant GIST-T1 cells. TP53 and SOCS6 may be the most promising candidate genes for imatinib-resistance due to the possible signaling pathway, such as apoptosis pathway and Wnt signaling pathway, JAK-STAT signaling pathway. It is necessary to perform more studies to discover novel targets in imatinib-resistant GIST, including DBP, NR3C1, TCF12, ZNF12, ZFP36, ACYP1 and DRD1.

Gambogic Acid Efficiently Kills Stem-Like Colorectal Cancer Cells by Upregulating ZFP36 Expression.

BACKGROUND/AIMS: Gambogic acid (GA), the main active compound of Gamboge hanburyi, has been reported to be a potential novel antitumor drug. Whether GA inhibits putative cancer stem cells (CSCs), which are considered to be the major cause of cancer treatment failure, remains largely unknown. This study investigated whether GA inhibits the CSCs of colorectal cancer (CRC) and its possible mechanisms. METHODS: We performed CCK8 and tumor sphere formation assays, percentage analysis of both side population and CD133+CD44+ cells, and the detection of stem cells markers, in order to assess the role of GA in inhibiting the stem celllike features of CRC. An mRNA microarray was performed to identify the downstream gene affected by GA and rescue assays were performed to further clarify whether the downstream gene is involved in the GA induced decrease of the stem cell-like CRC population. CRC cells were engineered with a CSC detector vector encoding GFP and luciferase (Luc) under the control of the Nanog promoter, which were utilized to investigate the effect of GA on putative CSC in human tumor xenograft-bearing mice using in vivo bioluminescence imaging. RESULTS: Our results showed that GA significantly reduced tumor sphere formation and the percentages of side population and CD133+CD44+ cells, while also decreasing the expression of stemness and EMT-associated markers in CRC cells in vitro. GA killed stem-like CRC cells by upregulating the expression of ZFP36, which is dependent on the inactivation of the EGFR/ ERK signaling pathway. GFP+ cells harboring the PNanog-GFP-T2A-Luc transgene exhibited CSC characteristics. The in vivo results showed that GA significantly inhibited tumor growth in nude mice, accompanied by a remarkable reduction in the putative CSC number, based on whole-body bioluminescence imaging. CONCLUSION: These findings suggest that GA significantly inhibits putative CSCs of CRC both in vitro and in vivo by inhibiting the activation of the EGFR/ ERK/ZFP36 signaling pathway and may be an effective drug candidate for anticancer therapies.

High expression of growth factor receptor-bound protein 14 predicts poor prognosis for colorectal cancer patients.

OBJECTS: To explore the roles of growth factor receptor-bound protein 14 (GRB14) in colorectal cancer (CRC) and its correlation with clinicopathological characteristics and prognosis of CRC patients. RESULTS: GRB14 was localized in the cytoplasm of CRC and benign glandular epithelium cells, showing higher levels in CRC tissues compared with normal colon samples (P < 0.001). High GRB14 was associated with a high pathological grade (P = 0.045), advanced clinical stage (P = 0.018), enhanced tumor invasion (P < 0.001) and lymph node metastasis (P = 0.028). The cancer genome atlas (TCGA) mRNA sequence data showed that GRB14 was upregulated in CRC at an advanced clinical stage (P = 0.011) with enhanced tumor invasion (P < 0.001) and lymph node metastasis (P = 0.014). Kaplan-Meier survival curves revealed that CRC patients with high GRB14 levels had a shorter survival compared with those showing low GRB14 expression (P = 0.007). High GRB14 expression was an independent prognostic factor for CRC patients (HR 2.847, 95 %CI 1.058-7.659; P = 0.038). CONCLUSIONS: GRB14 may be an important cancer promoter that enhances CRC progression. Upregulated GRB14 levels may predict a poor clinical outcome in CRC patients.

LINC00460/miR-186-3p/MYC feedback loop facilitates colorectal cancer immune escape by enhancing CD47 and PD-L1 expressions.

BACKGROUND: Long non-coding RNAs (LncRNAs) have been implicated as critical regulators of cancer tumorigenesis and progression. However, their functions and molecular mechanisms in colorectal cancer (CRC) still remain to be further elucidated. METHODS: LINC00460 was identified by differential analysis between human CRC and normal tissues and verified by in situ hybridization (ISH) and qRT-PCR. We investigated the biological functions of LINC00460 in CRC by in vitro and in vivo experiments. We predicted the mechanism and downstream functional molecules of LINC00460 by bioinformatics analysis, and confirmed them by dual luciferase reporter gene assay, RNA immunoprecipitation (RIP), RNA pull-down, etc. RESULTS: LINC00460 was found to be significantly overexpressed in CRC and associated with poor prognosis. Overexpression of LINC00460 promoted CRC cell immune escape and remodeled a suppressive tumor immune microenvironment, thereby promoting CRC proliferation and metastasis. Mechanistic studies showed that LINC00460 served as a molecular sponge for miR-186-3p, and then promoted the expressions of MYC, CD47 and PD-L1 to facilitate CRC cell immune escape. We also demonstrated that MYC upregulated LINC00460 expression at the transcriptional level and formed a positive feedback loop. CONCLUSIONS: The LINC00460/miR-186-3p/MYC feedback loop promotes CRC cell immune escape and subsequently facilitates CRC proliferation and metastasis. Our findings provide novel insight into LINC00460 as a CRC immune regulator, and provide a potential therapeutic target for CRC patients.

Seed and Soil: Consensus Molecular Subgroups (CMS) and Tumor Microenvironment Features Between Primary Lesions and Metastases of Different Organ Sites in Colorectal Cancer.

Purpose: Consensus molecular subtypes (CMS) are mainly used for biological interpretability and clinical stratification of colorectal cancer (CRC) in primary tumors (PT) but few in metastases. The heterogeneity of CMS distribution in metastases and the concordance of CMS between PT and metastases still lack sufficient study. We used CMS to classify CRC metastases and combine it with histopathological analysis to explore differences between PT and distant metastases. Patients and Methods: We obtained gene expression profiles for 942 PT samples from TCGA database (n=376) and GEO database (n=566), as well as 442 metastasis samples from GEO database. Among these, 765 PT samples and 442 metastasis samples were confidently identified with CMS using the "CMS classifier" and enrolled for analysis. Clinicopathological manifestation and CMS classification of CRC metastases were assessed with data from GEO, TCGA, and cBioPortal. Overall, 105 PT-metastasis pairs were extracted from 10 GEO datasets to assess CMS concordance. Tumor microenvironment (TME) features between PT and metastases were analyzed by immune-stromal infiltration with ESTIMATE and xCell algorithms. Finally, TME features were validated with multiplex immunohistochemistry in 27 PT-metastasis pairs we retrospectively collected. Results: Up to 64% of CRC metastases exhibited concordant CMS groups with matched PT, and the TME of metastases was similar to that of PT. For most common distant metastases, liver metastases were predominantly CMS2 and lung and peritoneal metastases were mainly CMS4, highlighting "seed" of tumor cells of different CMS groups had a preference for metastasis to "soil" of specific organs. Compared with PT, cancer-associated fibroblasts (CAF) reduced in liver metastases, CD4+T cells and M2-like macrophages increased in lung metastases, and M2-like macrophages and CAF increased in peritoneal metastases. Conclusion: Our findings underscore the importance of CMS-guided specific organ monitoring and treatment post-primary tumor surgery for patients. Differences in immune-stromal infiltration among different metastases provide targeted therapeutic opportunities for metastatic CRC.

Colon cancer patient with long-term colon stent placement: Case report and literature review.

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer mortality globally. Large bowel obstruction (occurring in 15-30% of patients with CRCs) accounts for approximately 80% of medical emergencies related to CRC. Currently, there is no standard treatment of this condition. The European Society of Gastrointestinal Endoscopy (ESGE) recommends self-expandable metal stent (SEMS) as a bridge (two weeks) to surgery for left-sided obstructing colon cancer. In the present report, we describe an 81-year-old male with colon cancer who underwent colon stent placement for 32 months, but later underwent radical resection. A follow-up of more than four-months revealed that his condition was normal. The history as well as application and advantages of SEMS are discussed in this report.

Risk Factors for Recurrence of Radically Resected Mucinous Colorectal Adenocarcinoma.

BACKGROUND: Mucinous adenocarcinoma (MA) is a subtype of colorectal cancer (CRC) associated with a higher incidence of local extension and worse survival compared to non-mucinous adenocarcinoma, but few studies have investigated surgery-related predictors for recurrence of MA. Therefore, we aimed to elucidate the predictors for local recurrence and remote metastasis of MA after surgery. PATIENTS AND METHODS: This study retrospectively analyzed 162 patients with mucinous colorectal adenocarcinoma (MAC) after radical resection. Analysis variables included demographics, clinical indicators, pathologic stage, surgical procedure, adjuvant therapy, and recurrence. Univariate and multivariate analyses were performed to investigate the risk factors for local and distant tumor relapse. RESULTS: A total of 162 patients (86 male) with a mean age of 58.26 years were included; 70.37% of patients had colonic tumors, and 29.63% had rectal tumors. The 5-year disease-free survival (DFS) rates for these patients were as follows: 100% for TNM stage I, 71.2% for stage II, and 47.8% for stage III. Five-year DFS rates of MAC, colonic and rectal MA were 62.0%, 65.8%, and 51.7%, respectively. Local recurrence occurred in 38 patients and distant metastasis in 33 patients. In univariate analysis, predictors for local recurrence of MAC were intraoperative blood loss, intraoperative transfusion, and N2 stage; and predictors for distant metastasis were male sex, CA199, CEA, intraoperative blood loss, T4 stage, and N2 stage. In multivariate analysis, predictors for local recurrence of MAC were intraoperative transfusion (P=0.04, OR=4.175) and N2 stage (P=0.000, OR=5.291), and predictors for distant metastasis were male sex (P=0.049, OR=2.410), CA199 (P=0.02, OR=1.003), and T4 stage (P=0.007, OR=4.006). CONCLUSION: Intraoperative transfusion and N2 stage were significant predictors for local recurrence. Male sex, CA199, and T4 stage were significant predictors for distant metastasis. Knowledge of the risk factors for postoperative recurrence provides a basis for logical approaches to treatment and follow-up of MAC.

Outcomes of Laparoscopic Surgery for Mucinous Colorectal Adenocarcinoma.

Background: Mucinous colorectal adenocarcinoma (MAC) has a higher incidence of local extension, leading to lower overall resection rates. Few studies have investigated the outcomes of laparoscopic surgery for MACs to date. Therefore, we aimed to elucidate the validity of laparoscopic surgery for mucinous adenocarcinoma (MAC). Methods: This study analyzed short-term and long-term outcomes between laparoscopic and open surgery for MACs from 2008 to 2018. Multivariate analyses were used to define prognostic factors of overall survival (OS) and disease-free survival (DFS). Results: Patients in the laparoscopy (LAP) group had significantly less blood loss, fewer days to first flatus and to diet, and shorter length of hospital stay. The 3-year and 5-year DFS rates for all stages combined were 65.7% and 62.5% in the LAP group compared with 60.5% and 57.6% in the open (OPEN) surgery group (P = .521). The 3-year and 5-year OS rates for all stages combined were 72.3% and 67.3% in the LAP group compared with 72.6% and 67.8% in the OPEN group (P = .934). OS and DFS in stage II, stage III, and pathological T4 (pT4) stage patients who underwent laparoscopic surgery did not differ from patients who underwent open surgery. Multivariate analysis showed that stage pT4, pN2, and carcinoembryonic antigen (CEA) were significant predictors of OS. Independent factors, including intraoperative blood transfusion, stage pT4, pN2, CEA, and CA19-9, carbohydrate antigen 19-9, have a great effect on DFS. Conclusions: Laparoscopic surgery is a safe and feasible option for mucinous colorectal AC, which provides faster postoperative recovery and less intraoperative blood loss.

Establishment of multiple diagnosis models for colorectal cancer with artificial neural networks.

The current study aimed to develop multiple diagnosis models for colorectal cancer (CRC) based on data from The Cancer Genome Atlas database and analysis with artificial neural networks in order to enhance CRC diagnosis methods. A genetic algorithm and mean impact value were used to select genes to be used as numerical encoded parameters to reflect cancer metastasis or aggression. Back propagation and learning vector quantization neural networks were used to build four diagnosis models: Cancer/Normal, M0/M1, carcinoembryonic antigen (CEA) <5/≥5 and Clinical stage I-II/III-IV. The performance of each model was evaluated by predictive accuracy (ACC), the area under the receiver operating characteristic curve (AUC) and a 10-fold cross-validation test. The ACC and AUC of the Cancer/Normal, M0/M1, CEA and Clinical stage models were 100%, 1.000; 87.14%, 0.670; 100%, 1.000; and 100%, 1.000, respectively. The 10-fold cross-validation test of the ACC values and sensitivity for each test were 93.75-99.39%, 1.0000; 80.58-88.24%, 0.9286-1.0000; 67.21-92.31%, 0.7091-1.0000; and 59.13-68.85%, 0.6017-0.6585, respectively. The diagnosis models developed in the current study combined gene expression profiling data and artificial intelligence algorithms to create tools for improved diagnosis of CRC.

PD-L1 promotes colorectal cancer stem cell expansion by activating HMGA1-dependent signaling pathways.

PD-L1 is critical for tumor cell escape from immune surveillance by inhibiting T cell function via the PD-1 receptor. Accumulating evidence demonstrates that anti-PD-L1 monoclonal antibodies might potently enhance antitumor effects in various tumors, but the effect of PD-L1 on colorectal cancer stem cells (CSCs) remains unclear. We observed high PD-L1 expression in CD133+CD44+ colorectal CSCs and CSC-enriched tumorspheres. Altering PD-L1 expression promoted colorectal CSC self-renewal by increasing the expression of stemness genes, the CD133+CD44+ cell population sizes and the ability to form tumorspheres. Additionally, PD-L1 expression was markedly increased in chemoresistant colorectal cancer (CRC) cells in vitro and in vivo. More importantly, PD-L1 enhanced CRC cell tumorigenicity in nude mice; the inoculation of 1 × 104 cells resulted in high tumor formation efficiency. Mechanistically, PD-L1 directly interacted with HMGA1, and HMGA1 upregulation by PD-L1 activated HMGA1-dependent pathways, including the PI3K/Akt and MEK/ERK pathways, and promoted CSC expansion. HMGA1 downregulation rescued the PD-L1-induced phenotypes, highlighting the role of HMGA1 in PD-L1-mediated colorectal CSC self-renewal. Moreover, PD-L1 expression was correlated with the expression of CSC markers and HMGA1 in clinical CRC specimens. Thus, PD-L1 could crucially contribute to the maintenance of CSC self-renewal by activating HMGA1-dependent signaling pathways.

Long noncoding RNA PVT1-214 promotes proliferation and invasion of colorectal cancer by stabilizing Lin28 and interacting with miR-128.

Long noncoding RNAs (lncRNAs) are implicated in human cancer, but their mechanisms of action are largely unknown. In this study, we investigated lncRNA alterations that contribute to colorectal cancer (CRC) through microarray expression profiling in CRC patient samples. Here, we report that the CRC-associated lncRNA PVT1-214 is a key regulator of CRC development and progression; patients with high PVT1-214 expression had a shorter survival and poorer prognosis. In vitro and in vivo investigation of the role of PVT1-214 revealed a complex integrated phenotype affecting cell growth, stem-like properties, migration, and invasion. Furthermore, using RNA pull-down and mass spectrometry, we found that Lin28 (also known as Lin28A), a highly conserved RNA-binding protein, is associated with PVT1-214. Strikingly, we found that PVT1-214 not only upregulated Lin28 protein expression in CRC cells by stabilizing Lin28, but also participated in crosstalk with Lin28 mRNA through competition for miR-128 binding, imposing an additional level of post-transcriptional regulation. In addition, we further show that PVT1-214 repressed expression of let-7 family miRNAs, which was abrogated by Lin28 knockdown. Taken together, our findings support a model in which the PVT1-214/Lin28/let-7 axis serves as a critical regulator of CRC pathogenesis, which may simulate a new direction for CRC therapeutic development.

Expression of EZH2 is associated with poor outcome in colorectal cancer.

Enhancer of zeste homolog 2 (EZH2), the critical component of polycomb group protein family, has been demonstrated to be overexpressed in various types of human cancer, including hepatocellular carcinoma, breast, bladder and lung cancer. The mechanism of how EZH2 promotes oncogenesis has also been well studied. However, little is known about the role of EZH2 in colorectal cancer (CRC). The main purpose of the present study was to analyze the association between EZH2 expression and the clinicopathological features of CRC. Therefore, the mRNA and protein expression levels were analyzed in tumor tissues and adjacent non-cancerous tissues by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. The expression of EZH2 was demonstrated to be significantly increased in tumor tissues compared with adjacent noncancerous tissues, according to the results of western blot analysis and RT-qPCR in the majority of cases. Patients with low EZH2 expression had a longer overall survival rate compared with those with high EZH2 expression. An analysis of the association between clinicopathological features and EZH2 expression indicated that high EZH2 expression was significantly associated with tumor stage, tumor size, histological differentiation and lymph node metastasis. Multivariate analysis demonstrated that high EZH2 expression was an independent predictor of overall survival. In conclusion, to the best of our knowledge, the data presented in the present study is the first to indicate that EZH2 is upregulated in CRC and may serve as a predictor of poor outcome for patients with CRC.

Overexpression of flavin-containing monooxygenase 5 predicts poor prognosis in patients with colorectal cancer.

The present study investigated the expression and clinical significance of flavin-containing monooxygenase 5 (FMO5) in colorectal cancer (CRC). The expression of FMO5 was detected by immunohistochemistry in 208 colon cancer tissues and 8 normal colon tissues. Then, the correlations of FMO5 expression with several clinicopathological features were evaluated. FMO5 mRNA expression from The Cancer Genome Atlas dataset was assessed for further validation. In addition, the association of the expression of FMO5 with prognosis was further evaluated by Kaplan-Meier survival curves and Cox proportional hazards model. The FMO5 protein level in colon cancer tissues was significantly higher than that in normal colon tissues (P<0.001). Overexpression of FMO5 was associated with an advanced clinical stage of cancer (P=0.018) and lymph node metastasis (P=0.03). The TCGA dataset also demonstrated that FMO5 was upregulated in CRC with advanced clinical stage (P=0.047), lymph node metastasis (P=0.045) and distant metastasis (P=0.030). The Kaplan-Meier survival curves showed that higher FMO5 mRNA indicated a shorter overall survival in patients with CRC compared with a low expression of FMO5 (P=0.029). Cox proportional hazards regression revealed that a high FMO5 mRNA level served as an independent prognostic factor for patients with CRC (hazard ratio, 2.865; 95% confidence interval, 1.116-7.355; P=0.029). A high expression of FMO5 may serve roles in colorectal carcinogenesis and distant metastasis. FMO5 may be an independent predictive factor for the prognosis of CRC.

Long non­coding RNA 00152 functions as a competing endogenous RNA to regulate NRP1 expression by sponging with miRNA­206 in colorectal cancer.

Colorectal cancer (CRC) is the third most common type of cancer; however, the molecular mechanisms underlying colorectal tumor metastasis and growth remain elusive. Recently, accumulating evidence has indicated that long non­coding RNAs (lncRNAs) play a critical role in CRC progression and metastasis; however, the biological role and clinical significance of lncRNA 00152 (lnc00152) in CRC remains largely unknown. Thus, in this study, lnc00152 expression was measured in 80 human CRC tissue samples, 40 non­cancerous tissue samples, and 3 CRC cell lines (SW480, SW620 and LoVo) using RT­qPCR. We examined the effects of lnc00152 on CRC cells following transfection with lnc00152 overexpression plasmid or respective siRNA in vitro and in vivo. Luciferase assays revealed the mechanism driving competitive endogenous RNA (ceRNA). We identified that lnc00152 was aberrantly overexpressed in colorectal tumors and cancer cells and that lnc00152 was modulated by miRNA­206. lnc00152 overexpression enhanced the proliferative and invasive ability of CRC cells in vitro, promoted tumor growth in vivo, and was associated with the shorter overall survival of patients with CRC. In addition, lnc00152 overexpression promoted epithelial-mesenchymal transition (EMT) and increased neuropilin­1 (NRP1) expression in the CRC cells. By contrast, lnc00152 silencing exerted a counteractive effect. Collectively, these findings demonstrate the critical role of lnc00152 in tumor growth and progression in CRC, and identify a novel therapeutic target associated with CRC development and progression.

Gambogic acid reverses oxaliplatin resistance in colorectal cancer by increasing intracellular platinum levels.

Resistance to oxaliplatin (L-OHP) is a major obstacle to successful chemotherapy in colorectal cancer (CRC). In the present study, the ability of gambogic acid (GA) to reverse L-OHP resistance in CRC LoVo cells was investigated. L-OHP-resistant LoVo/L-OHP cells were established by exposing them to increasing concentrations of L-OHP. GA-reversed L-OHP-sensitive LoVo/L-OHP/GA cells were established by exposure to 0.5 µmol/l GA for 2 weeks. A Cell Counting Kit-8 assay was used to assess levels of proliferation. Flow cytometry was applied to detect apoptosis rates. Transwell assays were used to analyse invasion. Inductively coupled plasma mass spectrometry was used to determine intracellular platinum (Pt) content. Western blot analysis was used to reveal the protein levels of Human copper transporter 1 (hCTR1), Copper-transporting p-type adenosine triphosphatases 1 (ATP7A) and Copper-transporting p-type adenosine triphosphatases 2 (ATP7B). LoVo/L-OHP and LoVo/L-OHP/GA cell lines were successfully established, and it was identified that L-OHP inhibited the proliferation of LoVo, LoVo/L-OHP and LoVo/L-OHP/GA cells in a dose-dependent manner. Compared with the parent LoVo cells, the anti-apoptosis and invasion properties of LoVo/L-OHP cells were enhanced, and were reversed by GA treatment. Intracellular Pt content was highest in the LoVo cells, followed by LoVo/L-OHP/GA cells, and then lowest in the LoVo/L-OHP cells. Downregulated hCTP1 and upregulated ATP7A and ATP7B were associated with L-OHP resistance, and GA reversed the resistance by increasing levels of hCTR1 and decreasing levels of ATP7A and ATP7B. In conclusion, GA has the potential ability to reverse L-OHP resistance in CRC cells by increasing intracellular Pt content, which it achieves by increasing hCTR1 levels and decreasing ATP7A and ATP7B levels. GA may represent a promising treatment agent for L-OHP resistance.

Gambogic acid potentiates the chemosensitivity of colorectal cancer cells to 5-fluorouracil by inhibiting proliferation and inducing apoptosis.

Chemotherapy using 5-fluorouracil (5-FU) for colorectal cancer (CRC) has low specificity and response rates, leading to severe side effects. Gambogic acid (GA), a traditional Chinese medicine, has multi-targeted anticancer effects, including growth inhibition and apoptosis induction. However, it is unclear whether a combination of 5-FU and GA has synergistic anticancer effects in CRC cells. In this study, SW480 and HCT116 human CRC cells and human intestinal epithelial cells (IECs) were treated with different concentrations of 5-FU, GA or 5-FU+GA. A Cell Counting kit-8 assay was conducted to quantify cell proliferation. The combination index (CI) was calculated and the median-effect principle was applied to analyze the interaction between 5-FU and GA. Flow cytometry was used to determine the percentage of cells undergoing apoptosis. Reverse transcription-quantitative polymerase chain reaction and western blotting were applied to measure P53, survivin and thymidylate synthase (TS) mRNA and protein levels. It was found that 5-FU+GA more pronouncedly inhibited cell growth and induced apoptosis, compared with either monotherapy. CI values <1 indicated the synergistic effects of the drugs. 5-FU+GA further decreased P53, survivin and TS mRNA and protein levels in the two CRC cell lines compared with single drugs, whereas increased P53 protein levels were observed in HCT116 cells. Moreover, 5-FU+GA did not increase cytotoxicity to IECs. These results demonstrate that GA enhances the anticancer effects of 5-FU on CRC cells. Combined treatment with 5-FU and GA is effective and safe for CRC cells, and may become a promising chemotherapy treatment.