Fruquintinib in metastatic colorectal cancer: a multicenter real-world analysis on efficacy, safety, and predictive and prognostic factors.

Background: Randomized trials have shown a survival benefit for fruquintinib over placebo in patients with metastatic colorectal cancer (mCRC) that progressed after standard therapies, but real-world prognostic analyses have been seldom reported. We evaluated survival, safety outcomes, and predictive and prognostic factors in patients treated with fruquintinib in a real-life setting. Methods: We conducted a multi-center study by collecting relevant data on patients with advanced colorectal cancer (CRC) who received fruquintinib, focusing on progression-free survival (PFS), overall survival (OS), and L3 skeletal muscle index (SMI), including safety follow-up. Results: From January 2020 to January 2022, a total of 140 patients were selected and included in this study. The cut-off date was 30 July 2022. The median follow-up time was 18.3 months (range, 6-29.3 months) and the median age of included cases was 63 years (range, 32-81 years). The median PFS and OS for the 140 patients was 6.3 and 12.6 months, respectively. The median PFS and OS for the 76 patients who were included in SMI analysis was 6.0 and 12.0 months, respectively. Multivariate analysis suggested brain metastasis {hazard ratio (HR) [95% confidence interval (CI)]: 2.779 (1.162-6.646), P=0.02}, decrease in SMI of >5% [HR (95% CI): 9.732 (2.201-43.028), P=0.003], and baseline carcinoembryonic antigen (CEA) level [HR (95% CI): 4.061 (1.391-11.858), P=0.01] as independent predictors of OS. The most common treatment-related adverse events (TRAEs) were hypertension (24, 17.1%), fatigue (21, 15%), and hand-foot syndrome (20, 14.3%); 9 (13.6%) and 15 (10.7%) patients had dose reduction and treatment discontinuation due to TRAEs respectively. Conclusions: The real-world efficacy and safety of fruquintinib in advanced CRC patients are numerically superior to that in the previous phase III studies. SMI, brain metastasis and CEA could serve as potential markers for patient selection.

Comprehensive bioinformatic analysis of MMP1 in hepatocellular carcinoma and establishment of relevant prognostic model.

Matrix metalloproteinase 1 (MMP1) encodes endopeptidases associated with degradation of multiple components of the extracellular matrix. This function has increasingly been considered to play a major proteolysis role in tumor invasion and metastasis. However, the relationship between MMP1 gene expression, tumor-immune microenvironment and prognosis in hepatocellular carcinoma patients remains mostly unclear. This study focused on a comprehensive analysis of MMP1 in hepatocellular carcinoma, specifically the prognosis and tumor-immune microenvironment. MMP1 expression was analyzed using TCGA database and clinical samples. MMP1 associated mechanisms, pathways, mutations and prognosis in hepatocellular carcinoma were evaluated. We also analyzed the tumor-immune microenvironment and corresponding treatments. Our research demonstrated that MMP1 expression was upregulated in patients with hepatocellular carcinoma and correlated with poor survival. A prognostic model was established and its performance evaluated. We also found and report various correlations between MMP1 and immune-related cells/genes, as well the potential therapeutic agents. These findings indicate that MMP1 can potentially be a promising prognostic biomarker and indicator of the tumor-immune microenvironment status in hepatocellular carcinoma.

Cancer-associated fibroblasts derived extracellular vesicles promote angiogenesis of colorectal adenocarcinoma cells through miR-135b-5p/FOXO1 axis.

Colorectal adenocarcinoma (COAD) is a prevalent malignant tumor. Cancer-associated fibroblasts (CAFs)-derived extracellular vesicles (EVs) (CAFs-EVs) are implicated in COAD treatment. This study explored the mechanism of CAFs-EVs in COAD. CAFs and normal fibroblast (NFs) were isolated from COAD tissues and adjacent normal tissues. Vimentin, α-SMA, and FAP expressions were detected. EVs were isolated from CAFs and identified. SW480 and HCT116 cells were co-incubated with EVs. The EV uptake and COAD cell malignant behaviors were assessed. EV-treated SW480 and HCT116 cells were co-cultured with human umbilical vein endothelial cells (HUVECs). Extensive analyses were conducted to examine HUVEC proliferation, migration, and angiogenesis, and miR-135b-5p expression in COAD cells, and SW480 and HCT116 cells. CAFs were transfected with the miR-135b-5p inhibitor. miR-135b-5p downstream targets were predicted. FOXO1 expression in the co-culture system was determined and then overexpressed to evaluate its role in HUVECs mediated by COAD cells. COAD mouse model was established by transplanting SW480 cells into nude mice and injecting with EVs. Tumor growth rate, volume, and weight were examined. Ki67, VEGF, CD34, FOXO1 expressions, and VEGF content were detected. CAFs-EVs promoted COAD cell malignant behaviors and COAD cells-mediated HUVEC proliferation, migration, and angiogenesis. CAFs-EVs delivered miR-135b-5p into COAD cells. miR-135b-5p targeted FOXO1. Inhibition of miR-135b-5p in EVs or overexpression of FOXO1 partially reversed the effect of EVs on promoting COAD-induced angiogenesis. CAFs-EVs promoted tumor proliferation and angiogenesis of COAD in vivo. CAFs-EVs delivered miR-135b-5p into COAD cells to downregulate FOXO1 and promote HUVECs proliferation, migration, and angiogenesis.

Cancer-associated fibroblasts-derived exosomes upregulate microRNA-135b-5p to promote colorectal cancer cell growth and angiogenesis by inhibiting thioredoxin-interacting protein.

OBJECTIVE: The role of exosomes in human cancers has been identified, while the effect of cancer-associated fibroblasts (CAFs)-derived exosomes (CAF-exos) transmitting microRNAs (miRNAs) on colorectal cancer (CRC) remains largely unknown. We aim to explore the impact of CAF-derived exosomal miR-135b-5p on CRC progression by targeting thioredoxin-interacting protein (TXNIP). METHODS: CRC tissues were collected to obtain CAF-exos, which were used to co-culture with LoVo and HT29 cells. The effect of miR-135b-5p and TXNIP on the in vivo growth, in vitro proliferation, apoptosis, migration, invasion and angiogenesis of CRC cells. miR-135b-5p and TXNIP expression in exosomes and CRC cells were detected and their targeting relationship was confirmed. RESULTS: MiR-135b-5p was upregulated whereas TXNIP was downregulated in CRC tissues and cells. The CAF-exos and CAF-exos upregulating miR-135b-5p promoted in vivo growth, in vitro proliferation, migration and invasion, and suppressed apoptosis of CRC cells, and also promoted the HUVEC angiogenesis. TXNIP was confirmed as a target of miR-135b-5p and overexpression of TXNIP could weaken the pro-CRC effect of exosomal miR-135b-5p, CONCLUSION: CAF-exos upregulate miR-135b-5p to promote CRC cell growth and angiogenesis by inhibiting TXNIP.

The influence of preoperative biopsy on the surgical method in breast cancer patients: a single-center experience of 3,966 cases in China.

BACKGROUND: The National Surgical Adjuvant Breast and Bowel Project (NSABP) B32 trial reported that the detection rate of sentinel lymph nodes by core needle biopsy (CNB) is higher than that by segmental resection. However, there are few reports regarding the detection rate of sentinel lymph nodes by vacuum-assisted breast biopsy (VABB). Therefore, we analyzed the impact of preoperative biopsy methods on the surgical modes of 3,966 patients with breast cancer in our center. METHODS: In total, 3,966 female breast cancer patients [clinical tumor node metastasis (TNM) stage I-III] were enrolled in this study. Preoperative pathological diagnosis methods included fine needle aspiration (FNA) biopsy, CNB, excision biopsy, and VABB. According to the time of diagnosis. The data were analysis by chi square test, variance analysis and the Kaplan-Meier time series in SPSS 22.0. RESULTS: There was a decrease in the number of patients that underwent excision biopsy (7.3% to 2.7%) and intraoperative freezing (89.4% to 28.9%) over time, while CNB exhibited an increasing trend (1.6% to 55.3%). The positive rates of VABB, CNB, excision biopsy, and FNA were 99.5%, 97.1%, 97.9%, and 82.2%, respectively, and the false negative rates were 0%, 1.8%, 0.34%, and 8.9%, respectively. The overall breast-conserving rate was 36.7%, while the breast-conserving rate for VABB was 57.1%. The axillary sentinel lymph node biopsy rate of cN0 patients was 48.3%, and the intraoperative frozen group (36.7%) and excision biopsy group (39.5%) were lower than the CNB (57.1%) and VABB (77.9%) groups. Until December 2019, there were 350 cases with tumor recurrence or metastasis. The methods of biopsy were not correlated to the cumulative survival time. CONCLUSIONS: Changes to the diagnosis and treatment of breast cancer has a profound impact on the method of tumor biopsy. VABB biopsy offers advantages such as accurate diagnosis, a greater volume of tissue taken at one time, minimally invasive and repeatable, and does not affect the surgical approach and prognosis of patients. It will gradually become the primary method of preoperative pathological evaluation of breast cancer.

HIFU for the treatment of difficult colorectal liver metastases with unsuitable indications for resection and radiofrequency ablation: a phase I clinical trial.

BACKGROUND: The goal of this study is to evaluate the safety and efficacy of high intensity focused ultrasound (HIFU) for patients with colorectal liver metastases (CRLM) but were contraindicated for resection and radiofrequency ablation. METHODS: Patients between 20 and 80 years of age with 1-3 liver metastases from colorectal cancer were selected. Included patients have had their primary lesions removed with no evidence of extrahepatic metastasis prior to the study. Ultrasound-guided HIFU was employed and target regions' ablation was achieved with repeated sonications from the deep to shallow regions of the tumors section by section. RESULTS: Thirteen patients were enrolled. The most common adverse events (AEs) were pain (n = 8), followed by fatigue (n = 7), increased aspartate aminotransferase (AST) (n = 7), increased alanine aminotransferase (ALT) (n = 5), and skin edema (n = 4). No grade ≥ 3 AEs occurred and while most patients (76.9%) achieved a complete response, three patients achieved a partial response. The objective response rate was 100% after the first HIFU treatment. Nine patients relapsed but the tumors were mostly isolated to the liver (8/9). The median follow-up period was 25 months. The 2-year progression-free survival (PFS) was 16.7%, and the median PFS was 9 months. Notably, the 2-year overall survival (OS) was 77.8%, and the median OS was 25 months. CONCLUSION: This study indicates that the HIFU treatment is safe, is able to achieve a good tumor response rate and long-term prognosis even when the foci were in high-risk locations, and should be considered for patients who were considered unsuitable for other local treatments.

Inhibition of MEIS3 Generates Cetuximab Resistance through c-Met and Akt.

INTRODUCTION: Although cetuximab has been widely used in the treatment of colon cancer, a large number of patients eventually develop drug resistance. Therefore, it is essential to clarify the mechanism of drug resistance. METHODS: In this study, we combined in silico analysis and a single guide RNA (sgRNA) library to locate cetuximab-sensitive genes. Cell proliferation, apoptosis, and cell cycle were assessed to validate the change in cetuximab sensitivity. Finally, western blotting was performed to detect changes in epidermal growth factor (EGFR) upstream and downstream genes. RESULTS: Using in silico analysis and the sgRNA library, MEIS3 was confirmed as the cetuximab-sensitive gene. Further experiments indicated that the expression of MEIS3 could determine the level of cetuximab. Meanwhile, MEIS3-inhibited cells were sensitive to mesenchymal epithelial transition factor (c-Met) and protein kinase B (Akt) inhibitors, which is related to the change in phosphorylation of c-Met and degradation of Akt. CONCLUSION: MEIS3 modified the sensitivity to cetuximab through c-Met and Akt.

Human alkaline ceramidase 2 promotes the growth, invasion, and migration of hepatocellular carcinoma cells via sphingomyelin phosphodiesterase acid-like 3B.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer. It has a poor prognosis because it is often diagnosed at the advanced stage when treatments are limited. In addition, HCC pathogenesis is not fully understood, and this has affected early diagnosis and treatment of this disease. Human alkaline ceramidase 2 (ACER2), a key enzyme that regulates hydrolysis of cellular ceramides, affects cancer cell survival, however its role in HCC has not been well characterized. Our results showed that ACER2 is overexpressed in HCC tissues and cell lines. In addition, high ACER2 protein expression was associated with tumor growth; ACER2 knockdown resulted in decreased cell growth and migration. Sphingomyelin phosphodiesterase acid-like 3B (SMPDL3B) promoted HCC cell growth, invasion, and migration; SMPDL3B knockdown had a significant inhibitory effect on HCC tumor growth in vivo. Moreover, ACER2 positively regulated the protein level of SMPDL3B. Of note, ACER2/SMPDL3B promoted ceramide hydrolysis and S1P production. This axis induced HCC survival and could be blocked by inhibition of S1P formation. In conclusion, ACER2 promoted HCC cell survival and migration, possibly via SMPDL3B. Thus, inhibition of ACER2/SMPDL3B may be a novel therapeutic target for HCC treatment.

Serum AKR1B10 predicts the risk of hepatocellular carcinoma - A retrospective single-center study.

OBJECTIVES: AKR1B10, first cloned from liver cancer tissues, has recently been reported to be up-regulated significantly in hepatocellular carcinoma (HCC) tissues, but the relationship between serum level of AKR1B10 and the risk of HCC is not understood. METHODS: 170 HCC patients and 120 health donors from October 2014 to March 2017 were recruited in the affiliated hospital of Guilin Medical University. Serum AKR1B10 in all cases were detected and in 30 HCC patients were analyzed preoperatively and postoperatively by Time-resolved fluoroimmunoassay. RESULTS: The level of serum AKR1B10 was significantly higher in HCC patients (1800.24±2793.79) than in health donors (129.34±194.129), and downregulation of serum AKR1B10 in HCC patients was observed after hepatectomy. When samples were grouped according to the serum level of AKR1B10 (≥232.7pg/ml), serum AKR1B10 positively correlated to serum AFP (χ2=6.295, P=0.012), ALT (χ2=18.803, P=0.000), AST (χ2=33.421, P=0.000), tumor nodule number (χ2=6.777, P=0.009), cirrhosis (χ2=43.458, P=0.000), and tumor size (χ2=6.042, P=0.014) in the Chi-square test. CONCLUSIONS: Diagnosis of HCC could be improved using the both predictors of serum AKR1B10 and AFP. AKR1B10 was thus considered to be a new serological biomarker for HCC.

High expression of CDH3 predicts a good prognosis for colon adenocarcinoma patients.

Colon adenocarcinoma (COAD) is one of the most common types of malignancy of the digestive system, and a better understanding of the molecular mechanisms will contribute to an improvement in the quality of life for COAD patients. Cadherin 3 (CDH3), a gene encoding P-cadherin, is a major component of adherens junctions and is closely associated with the occurrence and development of a variety of tumor types. However, the current knowledge regarding the role of CDH3 in COAD is limited. The present study aimed to identify the relative mRNA and protein expression levels of CDH3 in COAD tissues, and whether CDH3 had any influence on the survival rate of patients with COAD. Analysis of differentially expressed genes using the UALCAN database revealed that CDH3 was significantly upregulated in COAD tissues, and reverse transcription-quantitative PCR analysis further confirmed that CDH3 was upregulated in 48 COAD tissues compared with that in their paired normal tissues (n=48). Consistent with this, analysis of the Human Protein Atlas database indicated that the expression levels of the CDH3 protein were upregulated in COAD tissues (n=11) compared with those in normal tissues (n=3; P=0.0245). Next, the association between the mRNA levels of CDH3 and the survival rate of the COAD patients was analyzed using the UALCAN database, and the Kaplan-Meier curves revealed that the CDH3 high expression group (n=69) had a better overall survival compared with that of the CDH3 medium/low expression group (n=210; P=0.037). Furthermore, analysis of clinical data of a cohort from our hospital indicated that the median survival time for COAD patients with high (n=20) and low (n=20) CDH3 levels was 55.5 and 43.5 months, respectively, and there was a significant difference in the survival time between the two groups (P=0.0078). The above results verified that CDH3 was significantly upregulated in the COAD tissues and that high expression of CDH3 predicts a good prognosis for COAD patients.

miR-7-5p regulates the proliferation and migration of colorectal cancer cells by negatively regulating the expression of Krüppel-like factor 4.

Previous studies have demonstrated that microRNA-7-5p (miR-7-5p) functions as a tumor suppressor in certain types of human cancer. However, the role of miR-7-5p in colorectal cancer (CRC) remains to be investigated. Using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), the present study demonstrated that miR-7-5p was downregulated in CRC tissues and cell lines. In addition, low miR-7-5p expression is able to predict a poor 5-year overall survival rate for patients with CRC. In vitro studies revealed that miR-7-5p overexpression inhibits cell proliferation and migration. Furthermore, Krüppel-like factor 4 (KLF4), an oncogene in CRC, was validated as a direct target of miR-7-5p. KLF4 expression was negatively correlated with miR-7-5p expression in CRC tissues. Notably, KLF4 overexpression rescued the suppressive effects of miR-7-5p on CRC cell proliferation and migration. In summary, the results of this study demonstrated that miR-7-5p inhibits CRC proliferation and migration by targeting KLF4, which suggests that miR-7-5p is a potential molecular target for the treatment of human CRC.

The long noncoding RNA TPTE2P1 promotes the viability of colorectal cancer cells.

Long noncoding RNAs (lncRNAs) have important functions in tumor development and progression, including colorectal cancer (CRC), but their roles are not completely understood. In this study, the roles of the lncRNA transmembrane phosphoinositide 3-phosphatase and tensin homolog 2 pseudogene 1 (TPTE2P1), previously implicated in gallbladder cancer cell migration and invasion, were evaluated in CRC. In particular, quantitative polymerase chain reaction was used to quantify TPTE2P1 levels in tumor tissues and cell lines. The association between TPTE2P1 and survival was analyzed using the online tool OncoLnc. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, colony formation assays, and flow cytometry were used to evaluate the effects of TPTE2P1 on viability, cell cycle progression, and apoptosis. Signaling pathway proteins were quantitated by Western blot analysis. Finally, the role of TPTE2P1 was analyzed in vivo using mouse models. TPTE2P1 levels were significantly higher in CRC tissues than in adjacent normal tissues. Higher expression was associated with a poor survival rate. The silencing of TPTE2P1 led to cell cycle arrest at the S phase and thereby inhibited cell viability. TPTE2P1 knockdown also caused cancer cell apoptosis via the activation of the apoptosis regulator (BCL2)/caspase 3 signaling cascade. In addition, the inhibition of TPTE2P1 had suppressive effects on tumors in vivo. TPTE2P1 is upregulated in CRC and plays essential roles in the regulation of cell viability in vitro and tumor formation in vivo.

Exosomal neutral sphingomyelinase 1 suppresses hepatocellular carcinoma via decreasing the ratio of sphingomyelin/ceramide.

Neutral sphingomyelinase 1 (NSMase1) mediates caspase-3 activation and apoptosis. However, the role of NSMase1, especially exosome-borne NSMase1 in hepatocellular carcinoma (HCC), remains unclear. We report that NSMase1, which converts sphingomyelin (SM) to ceramide, was significantly downregulated in HCC tissues. Low NSMase1 expression predicted poor long-term survival of HCC patients. NSMase1 downregulation in HCC resulted in increased SM and reduced ceramide (Cer) that led to an increased SM/Cer ratio. Interestingly, NSMase1 and NSMase activity were also decreased in exosomes isolated from HCC tissues and cell lines. Furthermore, NSMase activity increased in exosomes isolated from the culture medium of L02 cells transfected with pEGFP-C3-NSMase1 (NSMase1-Exo). NSMase1-Exo suppressed HCC cell growth and induced apoptosis via reduction of the SM/Cer ratio. Thus, NSMase1 in exosomes inhibits HCC growth by decreasing the SM/Cer ratio.

Knockdown of stromal interaction molecule 1 inhibits proliferation of colorectal cancer cells by inducing apoptosis.

Stromal interaction molecule 1 (STIM1) is an endoplasmic reticulum Ca2+ sensor which has been reported to be overexpressed in numerous types of cancer, and is involved in the cell proliferation, invasion, migration and metastasis frequently observed in cancer. However, the role of STIM1 in colorectal cancer (CRC) remains unknown. The purpose of the present study was to investigate the effect of STIM1 in human CRC. The expression of STIM1 was specifically knocked down using lentivirus-mediated small hairpin RNA (shRNA) interference techniques in the CRC cell lines HCT116 and SW1116. Subsequently, the efficiency of infection was confirmed using green fluorescent protein (GFP)-positive signals. The knockdown efficiency was further determined using the reverse transcription-quantitative polymerase chain reaction and western blotting analysis. As a result, CRC cell lines with STIM1 silenced were successfully constructed and subsequently employed in a series of cell function assays. Knockdown of STIM1 significantly suppressed cell proliferation and colony formation, as revealed by an MTT and colony formation assay. Furthermore, it was identified that STIM1 silencing may promote cell apoptosis through the induction of mitochondria-associated apoptosis, as was identified by increased expression levels of B-cell lymphoma 2 (Bcl-2)-associated death promoter, Bcl-2-associated X protein and poly(ADP-ribose) polymerase cleavage. Therefore, STIM1 may serve a critical role in the progression of CRC by regulating cell proliferation and apoptosis, which may provide a potential therapeutic target for the treatment of CRC.

Serum sphingosine 1-phosphate in hepatocellular carcinoma patients is related to HBV infection.

PURPOSE: Serum predictors for early diagnosis of hepatocellular carcinoma (HCC) have been investigated. Sphingosine-1-phosphate (S1P) has been widely reported to promote the survival of many types of cancer cells. However, the potential of serum S1P as a diagnostic marker in HCC has not been well characterized. The aim of this study was to identify the relationship between serum S1P and the risk of HCC. METHODS: We retrospectively reviewed serum S1P in 63 HCC patients and 39 normal people. Receiver operating characteristic (ROC) curve analysis was performed to define the cut-off value of S1P in the serum. Chi-square test, t-test and multivariate regression analysis were used to investigate the association between serum S1P and individual clinicopathologic parameters. RESULTS: S1P showed significantly higher level in healthy subjects (1.372±0.116 µM) than that in patients (1.372±0.116 µM). Serum S1P in HCC patients was positively correlated to globulin (t = -3.122, p=0.003), hepatitis B virus (HBV) DNA copies (x2=4.386, p=0.036) and negatively related to AST (x2=2.870, p=0.09). Besides, part of the amount of serum S1P was negatively correlated to albumin (correlation coefficient (ß) = -0.056) and positively correlated to alanine aminotransferase (ALT) (ß=0.016) according to the regression analysis. CONCLUSIONS: These results suggested that serum S1P could be used as an auxiliary marker for HCC diagnosis, and used to monitor HBV infection in patients with HCC.

Tumor and serum gamma-glutamyl transpeptidase, new prognostic and molecular interpretation of an old biomarker in gastric cancer.

BACKGROUND: Gastric Cancer is one of the most lethal malignancies worldwide. Gamma-glutamyl transpeptidase (GGT) is an enzyme mainly involved in cellular glutathione homeostasis. We aim to explore the clinical value of GGT in gastric cancer. RESULTS: Among 322 patients enrolled, 65/82 patients were determined as GGT positive in serum/tumor, respectively. High tumor GGT expression is significantly associated with lymph node metastasis, histological subtype, and Her2 expression. Kaplan-Meier curve shows that high tumor GGT patients have shorter overall survival (P log-rank=0.001) and progress-free survival (P log-rank =0.001). Patients with both high tumor and serum GGT have the poorest prognosis. The multivariable Cox analysis shows that the hazard ratio of overall survival for high tumor GGT is 1.69 (95% CI 1.19-2.37). High serum GGT is a poor prognostic factor in adjuvant chemotherapy hazard ratio=2.18, 95%CI (1.15-4.47). These findings were further validated in six online datasets. Gene Sets Enrichment Analysis showed that GGT promotes cancer progression through EMT, KRAS, SRC and PKCA pathways. METHODS: Tumor GGT and serum GGT levels were evaluated with immuno-histochemistry staining and enzymatic assay, respectively. Kaplan-Meier curve and Cox regression model were used to test the association between GGT and gastric cancer prognosis. Independent datasets from Gene Expression Omnibus and Gene Sets Enrichment Analysis were applied to validate the findings and explore the potential mechanisms. CONCLUSION: Both tumor GGT and serum GGT are poor prognostic factors in gastric cancer. Patients with high tumor and serum GGT levels require more intense treatment and follow-up.

Knockdown of TCTN1 Strongly Decreases Growth of Human Colon Cancer Cells.

BACKGROUND Tectonic family member 1 (TCTN1), a member of the tectonic family, is involved in several developmental processes and is aberrantly expressed in multiple solid tumors. However, the expression and regulation of TCTN1 in human colorectal cancer (CRC) is still not clear. MATERIAL AND METHODS The expression of TCTN1 mRNA was first explored by using Oncomine microarray datasets. TCTN1 expression was silenced in human CRC cell lines HCT116 and SW1116 via RNA interference (RNAi). Furthermore, we investigated the effect of TCTN1 depletion on CRC cell growth by MTT, colony formation, and flow cytometry in vitro. RESULTS In this study, meta-analysis showed that the expressions of TCTN1 mRNA in CRC specimens were significantly higher than that in normal specimens. Knockdown of TCTN1 expression potently inhibited the abilities of cell proliferation and colony formation as determined. Flow cytometry analysis showed that depletion of TCTN1 could cause cell cycle arrest at the G2/M phase. In addition, Annexin V/7-AAD double-staining indicated that TCTN1 silencing promoted cell apoptosis through down-regulation of caspase 3 and Bcl-2 and upregulation of cleaved caspase 3 and PARP. CONCLUSIONS Our results indicate that TCTN1 may be crucial for CRC cell growth, providing a novel alternative to target therapies of CRC. Further research on this topic is warranted.

Metabolic reprogramming and AMPKα1 pathway activation by caulerpin in colorectal cancer cells.

Caulerpin, a secondary metabolite from the marine invasive green algae Caulerpa cylindracea is known to induce mitochondrial dysfunctions. In this study, the anticancer property of caulerpin was assessed in a panel of colorectal cancer cell lines. We demonstrated that caulerpin inhibited oxidative phosphorylation (OXPHOS) and facilitated an early intervention of the mitochondrial function, via inhibiting mitochondrial complex I, accompanied by the dissipation of mitochondrial membrane potential and a surge of reactive oxygen species (ROS) generation. Moreover, in response to the increment in AMP/ATP ratio, the energy sensor AMP-activated protein kinase (AMPK) was activated by caulerpin treatment in a calcium/calmodulin-dependent protein kinase 2 (CaMKK2)­dependent manner. Distinguished effect on glycolysis was observed at different time-points after caulerpin treatment. Glycolysis was enhanced after a short time treatment with caulerpin, associated with upregulation of glucose transporter 1 (GLUT1), hexokinase II (HKII) and 6-phosphofructo-2-kinase (PFKFB3) protein expressions. However, long-term activation of AMPK by caulerpin damaged the glycolysis and glucose metabolism in colorectal cells, finally causing cell death. The persistent effect of caulerpin was mediated by AMPKα1, rather than AMPKα2, to abolish cell viability through hindering mTORC1-4E-BP1 axis. Moreover, caulerpin synergized with the glycolytic inhibitor 3BP in inhibiting cellular proliferation both in vitro and in vivo. Our findings on the previously uncharacterized anticancer effects of caulerpin may provide potential therapeutic approaches targeting the colorectal carcinoma metabolism.

Inhibition of protein phosphatase 5 (PP5) suppresses survival and growth of colorectal cancer cells.

Protein phosphatase 5 (PP5) is a unique member of the protein phosphatases family that functions in multiple signaling pathways involved in DNA damage, cell cycle control, cell growth, and apoptosis. Recent evidence indicated that PP5 may play a role in cancer progression. In this study, we aimed to examine the biological effect of PP5 on cell growth and apoptosis in human colorectal cancer (CRC). We first knocked down PP5 expression in RKO cells via a short hairpin RNA containing lentivirus system. Then, methylthiazoletetrazolium assay, colony formation assay, and flow cytometry analysis were performed. The proliferation and colony formation ability of RKO cells were remarkably suppressed in PP5-silenced groups, as compared with control groups. Moreover, downregulation of PP5 resulted in a significant G0/G1 phase cell cycle arrest and an induction of apoptosis. In all, these results demonstrated the importance of PP5 in CRC cell growth, and it might be used as a potential therapeutic target for the treatment of CRC.