scholarly journals Transforming Growth Factor β Mediates Drug Resistance by Regulating the Expression of Pyruvate Dehydrogenase Kinase 4 in Colorectal Cancer

2016 ◽  
Vol 291 (33) ◽  
pp. 17405-17416 ◽  
Author(s):  
Yang Zhang ◽  
Yi Zhang ◽  
Liying Geng ◽  
Haowei Yi ◽  
Wei Huo ◽  
...  

Drug resistance is one of the main causes of colon cancer recurrence. However, our understanding of the underlying mechanisms and availability of therapeutic options remains limited. Here we show that expression of pyruvate dehydrogenase kinase 4 (PDK4) is positively correlated with drug resistance of colon cancer cells and induced by 5-fluorouracil (5-FU) treatment in drug-resistant but not drug-sensitive cells. Knockdown of PDK4 expression sensitizes colon cancer cells to 5-FU or oxaliplatin-induced apoptosis in vitro and increases the effectiveness of 5-FU in the inhibition of tumor growth in a mouse xenograft model in vivo. In addition, we demonstrate for the first time that TGFβ mediates drug resistance by regulating PDK4 expression and that 5-FU induces PDK4 expression in a TGFβ signaling-dependent manner. Mechanistically, knockdown or inhibition of PDK4 significantly increases the inhibitory effect of 5-FU on expression of the anti-apoptotic factors Bcl-2 and survivin. Importantly, studies of patient samples indicate that expression of PDK4 and phosphorylation of Smad2, an indicator of TGFβ pathway activation, show a strong correlation and that both positively associate with chemoresistance in colorectal cancer. These findings indicate that the TGFβ/PDK4 signaling axis plays an important role in the response of colorectal cancer to chemotherapy. A major implication of our studies is that inhibition of PDK4 may have considerable therapeutic potential to overcome drug resistance in colorectal cancer patients, which warrants the development of PDK4-specific inhibitors.

2021 ◽  
Vol 22 (15) ◽  
pp. 8117
Author(s):  
Nunzia D’Onofrio ◽  
Elisa Martino ◽  
Luigi Mele ◽  
Antonino Colloca ◽  
Martina Maione ◽  
...  

Understanding the mechanisms of colorectal cancer progression is crucial in the setting of strategies for its prevention. δ-Valerobetaine (δVB) is an emerging dietary metabolite showing cytotoxic activity in colon cancer cells via autophagy and apoptosis. Here, we aimed to deepen current knowledge on the mechanism of δVB-induced colon cancer cell death by investigating the apoptotic cascade in colorectal adenocarcinoma SW480 and SW620 cells and evaluating the molecular players of mitochondrial dysfunction. Results indicated that δVB reduced cell viability in a time-dependent manner, reaching IC50 after 72 h of incubation with δVB 1.5 mM, and caused a G2/M cell cycle arrest with upregulation of cyclin A and cyclin B protein levels. The increased apoptotic cell rate occurred via caspase-3 activation with a concomitant loss in mitochondrial membrane potential and SIRT3 downregulation. Functional studies indicated that δVB activated mitochondrial apoptosis through PINK1/Parkin pathways, as upregulation of PINK1, Parkin, and LC3B protein levels was observed (p < 0.0001). Together, these findings support a critical role of PINK1/Parkin-mediated mitophagy in mitochondrial dysfunction and apoptosis induced by δVB in SW480 and SW620 colon cancer cells.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15118-e15118
Author(s):  
S. Lin ◽  
E. Chiang ◽  
Y. Tsai ◽  
S. Lee ◽  
B. Kuo ◽  
...  

e15118 Background: While clinical benefit against colorectal cancer has been observed with therapeutic monoclonal antibodies such as bevacizumab, cetuximab and panituzumab, the death rate of advanced colorectal cancer remains high that warrants further development of more potent therapeutics. Methods: A cell-based immunization approach was used to generate monoclonal antibodies against targets expressed on human colorectal cancer cells. A chimeric monoclonal antibody, AbGn-7, was selected and evaluated for the potential clinical use to treat colorectal cancer. Results: Expression of AbGn-7 antigen: Carbohydrate competition assay demonstrated that AbGn-7 recognizes a Lewis-A-like carbohydrate antigen (AbGn-7 antigen). Immunohistochemical studies showed that AbGn-7 antigen is expressed in colorectal cancer tissue. No significant binding could be detected in non-tumor tissues except in the epithelia of GI track. Effector function of AbGn-7: AbGn-7 triggered dose-dependent apoptosis in COLO 205 colon cancer cell. In addition, AbGn-7 elicited potent complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) in a dose-dependent manner. Molecular mechanism of apoptosis induced by AbGn-7: Tunel assay, PARP cleavage assay as well as caspase inhibitor studies demonstrated that AbGn-7 induced apoptosis in COLO 205 colon cancer cells via a caspase-independent pathway. Xenograft study: AbGn-7 alone, or in combination with 5FU-Leucovorin, effectively inhibited the growth of COLO 205 xenograft in SCID mice and prolonged their survival. Conclusions: The results of the present study suggest that AbGn-7 is a potential candidate for effective treatment of colorectal cancer. [Table: see text]


2019 ◽  
Vol 18 (15) ◽  
pp. 2149-2155
Author(s):  
Danial Seyfi ◽  
Seyed B. Behzad ◽  
Mohammad Nabiuni ◽  
Kazem Parivar ◽  
Mohammad Tahmaseb ◽  
...  

Objective: Metastasis phenotype is considered as the main challenge in colon cancer therapeutic methods. Furthermore, the side effects of conventional colorectal cancer treatment methods have attracted a lot of attention into natural ingredients. The aim of the study was to assess the molecular mechanism of verbascoside as natural bio-compound in human HT29 colon cancer cells. Methods: HT29 cells were cultured in RPMI-1640 medium containing 10% FBS and 1% penicillin/ streptomycin at 37°C and 5% CO2. HT-29 cells were treated with different concentrations of verbascoside (10, 20, 30, 40, 50, 70, 100 µg/ml) for 24 hours, then MTT assay was used to calculate 50% inhibitory concentration. The migration of the colon cancer cells was evaluated by scratch assay. To evaluate involved antiproliferative mechanism, Rac-1 (Ras-related C3 botulinum toxin substrate 1) and HIF-1α (hypoxia-inducible factor-1α) related gene expression were evaluated by Real Time PCR. Results: The results showed that verbascoside inhibited HT29 colon cancer cell proliferation dose-dependently and IC50 was evaluated as 50 μg/ml (***P<0.001). The results of wound healing assay demonstrated verbascoside decreased cell migration in a dose dependent manner. In the IC50 treated HT29 cells metastatic progression was significantly suppressed as **P<0.01. The results of Real Time PCR showed an attenuating effect of verbascoside on Rac-1, Zeb-1 (zinc finger E-box binding homeobox 1), Arp2 (Actin-Related Proteins), Pak1 (p21 (RAC1) activated kinase 1), VEGF (Vascular endothelial growth factor) and HIF-1α as Epithelial-Mesenchymal Transition markers. The down regulation of mRNA levels was Rac-1= 15.38, HIF-1 α = 16.66, Pak-1, Arp-2= 6.25, VEGF=24.39, Zeb-1=35.71 in HT29 cells treated with IC50 concentration of verbascoside. Conclusion: Colorectal cancer cells induce Rac-1 and HIF-1α overexpression which plays an important role in the activation and progression of cell motility, angiogenesis and metastasis. Overall results showed that verbascoside elucidated significant anti-metastatic and anti-invasion activities through suppression of Rac-1, HIF-1α, and Zeb-1 signaling pathway and it may be a suitable candidate to overwhelm colon cancer metastatic phenotype.


2021 ◽  
Vol 22 (11) ◽  
pp. 5566
Author(s):  
Junyan Qu ◽  
Cheng Zeng ◽  
Tingting Zou ◽  
Xu Chen ◽  
Xiaolong Yang ◽  
...  

Colorectal cancer (CRC) is the third leading malignant tumor in the world, which has high morbidity and mortality. In this study we found that trichodermic acid (TDA), a secondary metabolite isolated from the plant endophytic fungus Penicillium ochrochloronthe with a variety of biological and pharmacological activities, exhibited the antitumor effects on colorectal cancer cells in vitro and in vivo. Our results showed that TDA inhibited the proliferation of colon cancer cells in a dose-dependent manner. TDA induces sustained endoplasmic reticulum stress, which triggers apoptosis through IRE1α/XBP1 and PERK/ATF4/CHOP pathways. In addition, we found that TDA mediated endoplasmic reticulum stress also induces autophagy as a protective mechanism. Moreover, combined treatment of TDA with autophagy inhibitors significantly enhanced its anticancer effect. In conclusion, our results indicated that TDA can induce ER stress and autophagy mediated apoptosis, suggesting that targeting ER stress and autophagy may be an effective strategy for the treatment of CRC.


2021 ◽  
Author(s):  
Antony W Burgess ◽  
Maree C Faux ◽  
Silvia Paola Corona ◽  
Janet Weinstock ◽  
Guillaume Lessene ◽  
...  

Colorectal cancer (CRC) is driven by a small set of oncogenic and tumor suppressor mutations. However, different combinations of mutations often lead to poor tumor responses to individual anti-cancer drugs. We have investigated the anti-proliferative and in vitro cytotoxic activity of pair-wise combinations of inhibitors which target specific signaling pathways. Colon cancer cells in non-adherent cultures were killed more effectively by combinations of pyrvinium pamoate (a Wnt pathway inhibitor) and ABT263 (a pro-apoptotic Bcl-2 family inhibitor) or Ly29004 (a PI3kinase inhibitor). However, in a mouse xenograft model, the formulation and toxicity of the ABT737/PP combination prevent the use of these drugs for treatment of tumors. Fortunately, oral analogues of PP (pyrvinium phosphate, PPh) and ABT737(ABT263) have equivalent activity and can be used for treatment of mice carrying SW620 colorectal cancer xenografts. The PPh/ABT263 induced SW620 tumor cell apoptosis and reduced the rate of SW620 tumor growth. Combinations of Wnt signaling inhibitors and specific inhibitor of pro-survival proteins should be considered for the treatment of precancerous colon adenomas and advanced colorectal cancers with APC mutations.


2013 ◽  
Vol 43 (4) ◽  
pp. 1111-1116 ◽  
Author(s):  
WARAPORN MALILAS ◽  
SANG SEOK KOH ◽  
SEOKHO KIM ◽  
RATAKORN SRISUTTEE ◽  
IL-RAE CHO ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ling Jin ◽  
Eun-Yeong Kim ◽  
Tae-Wook Chung ◽  
Chang Woo Han ◽  
So Young Park ◽  
...  

AbstractMost cancer cells primarily produce their energy through a high rate of glycolysis followed by lactic acid fermentation even in the presence of abundant oxygen. Pyruvate dehydrogenase kinase (PDK) 1, an enzyme responsible for aerobic glycolysis via phosphorylating and inactivating pyruvate dehydrogenase (PDH) complex, is commonly overexpressed in tumors and recognized as a therapeutic target in colorectal cancer. Hemistepsin A (HsA) is a sesquiterpene lactone isolated from Hemistepta lyrata Bunge (Compositae). Here, we report that HsA is a PDK1 inhibitor can reduce the growth of colorectal cancer and consequent activation of mitochondrial ROS-dependent apoptotic pathway both in vivo and in vitro. Computational simulation and biochemical assays showed that HsA directly binds to the lipoamide-binding site of PDK1, and subsequently inhibits the interaction of PDK1 with the E2 subunit of PDH complex. As a result of PDK1 inhibition, lactate production was decreased, but oxygen consumption was increased. Mitochondrial ROS levels and mitochondrial damage were also increased. Consistent with these observations, the apoptosis of colorectal cancer cells was promoted by HsA with enhanced activation of caspase-3 and -9. These results suggested that HsA might be a potential candidate for developing a novel anti-cancer drug through suppressing cancer metabolism.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1261
Author(s):  
Nurul Fattin Che Rahim ◽  
Yazmin Hussin ◽  
Muhammad Nazirul Mubin Aziz ◽  
Nurul Elyani Mohamad ◽  
Swee Keong Yeap ◽  
...  

Colorectal cancer (CRC) is the third most common type of cancer worldwide and a leading cause of cancer death. According to the Malaysian National Cancer Registry Report 2012–2016, colorectal cancer was the second most common cancer in Malaysia after breast cancer. Recent treatments for colon cancer cases have caused side effects and recurrence in patients. One of the alternative ways to fight cancer is by using natural products. Curcumin is a compound of the rhizomes of Curcuma longa that possesses a broad range of pharmacological activities. Curcumin has been studied for decades but due to its low bioavailability, its usage as a therapeutic agent has been compromised. This has led to the development of a chemically synthesized curcuminoid analogue, (2E,6E)-2,6-bis(2,3-dimethoxybenzylidine) cyclohexanone (DMCH), to overcome the drawbacks. This study aims to examine the potential of DMCH for cytotoxicity, apoptosis induction, and activation of apoptosis-related proteins on the colon cancer cell lines HT29 and SW620. The cytotoxic activity of DMCH was evaluated using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) cell viability assay on both of the cell lines, HT29 and SW620. To determine the mode of cell death, an acridine orange/propidium iodide (AO/PI) assay was conducted, followed by Annexin V/FITC, cell cycle analysis, and JC-1 assay using a flow cytometer. A proteome profiler angiogenesis assay was conducted to determine the protein expression. The inhibitory concentration (IC50) of DMCH in SW620 and HT29 was 7.50 ± 1.19 and 9.80 ± 0.55 µg/mL, respectively. The treated cells displayed morphological features characteristic of apoptosis. The flow cytometry analysis confirmed that DMCH induced apoptosis as shown by an increase in the sub-G0/G1 population and an increase in the early apoptosis and late apoptosis populations compared with untreated cells. A higher number of apoptotic cells were observed on treated SW620 cells as compared to HT29 cells. Human apoptosis proteome profiler analysis revealed upregulation of Bax and Bad proteins and downregulation of Livin proteins in both the HT29 and SW620 cell lines. Collectively, DMCH induced cell death via apoptosis, and the effect was more pronounced on SW620 metastatic colon cancer cells, suggesting its potential effects as an antimetastatic agent targeting colon cancer cells.


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