Biosynthesis Zinc Oxide Nanoparticles Using Senna Occidentalis Leaf Extract and Evaluation of their Cytotoxic Effect on SW480 Colon Cancer Cell Line

ObjectiveIn the present study, we green synthesized ZnO NPs (zinc oxide nanoparticles) from Senna occidentalis leaf extract which were subsequently assessed for their cytotoxic and antioxidant activity on colon cancer SW480 cell line.Results Zinc oxide nanoparticles were characterized by using UV-Vis spectroscopy, X-ray diffractometer (XRD), Particle size analyzer (PSA), Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray (EDS) and atomic force microscope (AFM) analysis. The PSA, XRD and AFM showed 20-50 nm size and nearly cuboidal and irregular shaped of the ZnO NPs. The synthesized ZnO nanoparticles were evaluated for their anticancer activity on human colon cancer cell line (SW480) by using MTT and neutral red uptake assay. The SW480 colon cancer cells were treated with various concentrations of ZnO NPs in the range of 20–100 µg/ml for 2 hrs. The result showed that ZnO NPs could reduce cell viability of SW480 cells up to 50% at the concentration of 100 µg/ml and induce membrane leakage in a concentration dependent manner.ConclusionThe anticancer activity of zinc oxide nanoparticles has showed that these can be used as effective anti-cancer agent against colon cancer cell lines (SW480).

RAB27A Promotes the Proliferation and Invasion of Colorectal Cancer Cells

Colorectal cancer (CRC) is the most commonly diagnosed form of cancer worldwide. Though significant advances in prevention and diagnosis, CRC is still one of the leading causes of cancer-related mortality globally. RAB27A, the member of RAB27 family of small GTPases, is the critical protein for intracellular secretion and was reported to promote tumor progression. However, it is controversial for the role of RAB27A in CRC progression, so we explored the exact function of RAB27A in CRC development in this study. Based on the stable colon cancer cell lines of RAB27A knockdown and ectopic expression, we found that RAB27A knockdown inhibited SW480 colon cancer cell proliferation and clone formation, whereas ectopic expression of RAB27A in RKO colon cancer cells facilitated cell proliferation and clone formation, indicating that RAB27A is critical for colon cancer cell growth. In addition, our data demonstrated that the migration and invasion of colon cancer cells were suppressed by RAB27A knockdown, but promoted by RAB27A ectopic expression. Therefore, RAB27A was identified as an onco-protein in mediating CRC development, which may be a valuable prognostic indicator and potential therapeutic target for CRC.

Knockdown of OLR1 weakens glycolytic metabolism to repress colon cancer cell proliferation and chemoresistance by downregulating SULT2B1 via c-MYC

Chemoresistance is one of the major problems of colon cancer treatment. In tumors, glycolytic metabolism has been identified to promote cell proliferation and chemoresistance. However, the molecular mechanisms underlying glycolytic metabolism and chemoresistance in colon cancer remains enigmatic. Hence, this research was designed to explore the mechanism underlying the OLR1/c-MYC/SULT2B1 axis in the regulation of glycolytic metabolism, to affect colon cancer cell proliferation and chemoresistance. Colon cancer tissues and LoVo cells were attained, where OLR1, c-MYC, and SULT2B1 expression was detected by immunohistochemistry, RT-qPCR, and western blot analysis. Next, ectopic expression and knockdown assays were implemented in LoVo cells. Cell proliferation was detected by MTS assay and clone formation. Extracellular acidification, glucose uptake, lactate production, ATP/ADP ratio, and GLUT1 and LDHA expression were measured to evaluate glycolytic metabolism. Then, the transfected cells were treated with chemotherapeutic agents to assess drug resistance by MTS experiments and P-gp and SMAD4 expression by RT-qPCR. A nude mouse model of colon cancer transplantation was constructed for in vivo verification. The levels of OLR1, c-MYC, and SULT2B1 were upregulated in colon cancer tissues and cells. Mechanistically, OLR1 increased c-MYC expression to upregulate SULT2B1 in colon cancer cells. Moreover, knockdown of OLR1, c-MYC, or SULT2B1 weakened glycolytic metabolism, proliferation, and chemoresistance of colon cancer cells. In vivo experiments authenticated that OLR1 knockdown repressed the tumorigenesis and chemoresistance in nude mice by downregulating c-MYC and SULT2B1. Conclusively, knockdown of OLR1 might diminish SULT2B1 expression by downregulating c-MYC, thereby restraining glycolytic metabolism to inhibit colon cancer cell proliferation and chemoresistance.

The Expression of YKL-40 in Peripheral Blood of Colorectal Cancer and Its Effect on the Proliferation and Angiogenesis of Colorectal Cancer Cells

Objective To observe the expression of YKL-40 in the serum of patients with colorectal cancer, and to study the effect of YKL-40 gene on the proliferation and angiogenesis of colon cancer cell lines. Methods The serum of patients with colorectal cancer, precancerous lesions, and healthy controls were collected, and the expression of YKL-40 was detected by enzyme-linked immunosorbent assay (ELISA) technology. Screened cell lines with high expression of YKL-40 from colon cancer cell lines HCT-15, HCT-116, SW480, interfered with YKL-40 gene expression through siRNA technology, and co-cultured with bevacizumab, and detected cells with CCK8 method Proliferation, cell formation test to detect blood vessel formation. Results The mean values of serum YKL-40 in the colorectal cancer group, precancerous lesion group and control group were (178.50±71.91) μg/L, (91.37±35.79) μg/L and (78.23±26.52) μg/L, respectively. The colorectal cancer group (preoperative) was significantly higher than the precancerous lesion group and the control group (P <0.01). The precancerous lesion group was higher than the control group, but the difference between the two was not statistically significant (P = 0.244). The expression of YKL-40 was positively correlated with the stage of colorectal cancer (P <0.05). There was no significant difference in the expression of serum YKL-40 before and after surgery (p=0.07). HCT-116 is a YKL-40 highly expressing cell line. After inhibiting the expression of this gene, the survival rate of the experimental group was 78.75%, which was significantly lower than that of the control group (p<0.05). The angiogenesis test is used to detect the angiogenesis ability. siRNA interference with YKL-40 gene and the addition of bevacizumab can inhibit the angiogenesis ability in vitro. Moreover,the vascular inhibitory effect of bevacizumab in the experimental group was stronger than that in the control group. Conclusion YKL-40 is highly expressed in the peripheral blood of patients with colorectal cancer and is related to the tumor stage. The HCT-116 colon cancer cell line has a high expression of YKL-40. Interfering with the expression of YKL-40 can inhibit cell proliferation and angiogenesis. It suggests that YKL-40 plays an important role in the occurrence and development of colorectal cancer.

Peroxiporins Are Induced Upon Oxidative Stress Insult and Are Associated with Oxidative Stress Resistance in Colon Cancer Cell Lines

Oxidative stress can induce genetic instability and change cellular processes, resulting in colorectal cancer. Additionally, adaptation of oxidative defense causes therapy resistance, a major obstacle in successful cancer treatment. Peroxiporins are aquaporin membrane channels that facilitate H2O2 membrane permeation, crucial for regulating cell proliferation and antioxidative defense. Here, we investigated four colon cancer cell lines (Caco-2, HT-29, SW620, and HCT 116) for their sensitivity to H2O2, cellular antioxidative status, and ROS intracellular accumulation after H2O2 treatment. The expression of peroxiporins AQP1, AQP3, and AQP5 and levels of NRF2, the antioxidant transcription factor, and PPARγ, a transcription factor that regulates lipid metabolism, were evaluated before and after oxidative insult. Of the four tested cell lines, HT-29 was the most resistant and showed the highest expression of all tested peroxiporins and the lowest levels of intracellular ROS, without differences in GSH levels, catalase activity, nor NF2 and PPARγ levels. Caco-2 shows high expression of AQP3 and similar resistance as HT-29. These results imply that oxidative stress resistance can be obtained by several mechanisms other than the antioxidant defense system. Regulation of intracellular ROS through modulation of peroxiporin expression may represent an additional strategy to target the therapy resistance of cancer cells.

ABHD5 inhibits YAP-induced c-Met overexpression and colon cancer cell stemness via suppressing YAP methylation

Cancer stemness represents a major source of development and progression of colorectal cancer (CRC). c-Met critically contributes to CRC stemness, but how c-Met is activated in CRC remains elusive. We previously identified the lipolytic factor ABHD5 as an important tumour suppressor gene in CRC. Here, we show that loss of ABHD5 promotes c-Met activation to sustain CRC stemness in a non-canonical manner. Mechanistically, we demonstrate that ABHD5 interacts in the cytoplasm with the core subunit of the SET1A methyltransferase complex, DPY30, thereby inhibiting the nuclear translocation of DPY30 and activity of SET1A. In the absence of ABHD5, DPY30 translocates to the nucleus and supports SET1A-mediated methylation of YAP and histone H3, which sequesters YAP in the nucleus and increases chromatin accessibility to synergistically promote YAP-induced transcription of c-Met, thus promoting the stemness of CRC cells. This study reveals a novel role of ABHD5 in regulating histone/non-histone methylation and CRC stemness.