BACKGROUND: Dendritic cell (DC)-based tumor vaccine is an attractive modality for the treatment of colon cancer because it has been recurred and produced few side effects in patients. Secretory glycoprotein 90K has been found at elevated level in various cancer tissues and sera. We investigated to establish a more effective DC vaccine for the treatment of colon cancer in which the levels of 90K are elevated. METHODS: We obtained the concentrated 90K from 293T cells stably expressing 90K. DCs were cultured from peripheral blood monocytes, and a DC vaccine pulsed with tumor lysate was compared with a DC vaccine pulsed with 90K. We measured the functional activity for CTLs by using IFN-gamma-enzyme linked immunoabsorbent spot (ELISPOT) assay. RESULTS: DCs pulsed with tumor lysate+90K exhibited the enhanced T cell stimulation, polarization of naive T cell toward Th1. The CTLs generated by DCs pulsed with 90K efficiently lysed HCT116 cells. The results indicate that 90K-speicifc-CTLs can recognize 90K proteins naturally presented by colon cancer cells. CONCLUSION: Our study suggests that 90K-specific CTLs generated by 90K-pulsed DCs could be useful effector cells for immunotherapy in colon cancer.
Colon ; Colonic Neoplasms ; Dendritic Cells ; Glycoproteins ; HCT116 Cells ; Humans ; Immunotherapy ; Monocytes ; Proteins ; T-Lymphocytes, Cytotoxic

Under normal, non-stressed conditions, intracellular p53 is continually ubiquitinated by MDM2 and targeted for degradation. However, in response to severe genotoxic stress, p53 protein levels are markedly increased and apoptotic cell death is triggered. Inhibiting the ubiquitination of p53 under conditions where DNA damage has occurred is therefore crucial for preventing the development of cancer, because if cells with severely damaged genomes are not removed from the population, uncontrolled growth can result. However, questions remain about the cellular mechanisms underlying the regulation of p53 stability. In this study, we show that p53-inducible gene 3 (PIG3), which is a transcriptional target of p53, regulates p53 stability. Overexpression of PIG3 stabilized both endogenous and transfected wild-type p53, whereas a knockdown of PIG3 lead to a reduction in both endogenous and UV-induced p53 levels in p53-proficient human cancer cells. Using both in vivo and in vitro ubiquitination assays, we found that PIG3 suppressed both ubiquitination- and MDM2-dependent proteasomal degradation of p53. Notably, we demonstrate that PIG3 interacts directly with MDM2 and promoted MDM2 ubiquitination. Moreover, elimination of endogenous PIG3 in p53-proficient HCT116 cells decreased p53 phosphorylation in response to UV irradiation. These results suggest an important role for PIG3 in regulating intracellular p53 levels through the inhibition of p53 ubiquitination.
Apoptosis ; Cell Death ; DNA Damage ; Genome ; HCT116 Cells ; Humans ; In Vitro Techniques ; Phosphorylation ; Ubiquitin* ; Ubiquitination*

BACKGROUND: Genistein and daidzein are two major soybean isoflavones. They have received increasing attention because of their possible roles for cancer prevention. However, their mechanisms of action and molecular targets on the human colon cancer cells are not fully understood. METHODS: Human colon cancer HCT-116 cells were treated with genistein and daidzein to investigate their effects on the cell growth and this was analyzed with MTT assay. TUNEL assay and Hoechst33342 stain were carried out to identify apotosis. RESULTS: Daidzein was able to inhibit cell proliferation and induce apoptosis of the HCT-116 cells, but genistein didn't affect the cell growth. The ER antagonist ICI182780 didn't attenuate the antiproliferative and proapoptotic effects of daidzein: this means the effect of daidzein on the HCT-116 cells may not be dependent on the ER pathway. The other soybean isoflavone, genistein, attenuated the effects of daidzein on the HCT-116 cells and its mechanism should be elucidated. CONCLUSIONS: These data suggest that daidzein may act as a preventive agent on human colon cancer, and its mechanism of action doesn't involve the ER-dependent pathway.
Apoptosis ; Cell Proliferation ; Colon* ; Colonic Neoplasms* ; Genistein* ; HCT116 Cells* ; Humans* ; In Situ Nick-End Labeling ; Isoflavones ; Soybeans

OBJECTIVETo determine whether lysosome-associated protein transmembrane-4 beta (LAPTM4B) over-expression is associated with the proliferation and invasion in colorectal cancer (CRC).

METHODSThirty pairs of CRC tissues, containing carcinoma and adjacent tissues, were used for the examination of LAPTM4B mRNA expression by real-time quantitative PCR (qPCR) assays. Then immunohistochemistry was performed to examine LAPTM4B protein expression in 6 pairs of CRC tissues. Over-expression LAPTM4B and low-expression LAPTM4B cell models were constructed with HCT116 CRC cell lines. CCK8 assay was used to detect the proliferation and Transwell assay was used to detect the invasion of the model cells.

RESULTSqPCR and immunohistochemistry results showed that LAPTM4B expression levels in CRC were higher compared to adjacent tissues (all P<0.01). CCK8 and Transwell assays results showed that LAPTM4B promoted proliferation and invasion of HCT116 cell lines model cells (all P<0.01).

CONCLUSIONLAPTM4B promotes the proliferation and invasion in CRC patients, and may be used as an important potential marker.

Cell Proliferation ; Colorectal Neoplasms ; HCT116 Cells ; Humans ; Immunohistochemistry ; Membrane Proteins ; Neoplasm Invasiveness ; Oncogene Proteins

MicroRNAs are negative regulators of mRNA, and latest studies show that "mRNAs can also inhibit microRNAs". With these reciprocal interactions, different mRNAs with identical "microRNA binding site" cim regulate each other by competitively binding to the same microRNA pool. This is the novel competing endogenous RNA (ceRN A)regulating mechanism. The ceRN A mechanism, which is a totally new regulating mechanism , greatly expands the regulatory network across genes. It has been proved by experimental evidence that, in HCT116 colon cancer cells,KRAS and PTEN , ZEB2 and PTEN can regulate each other by ceRNA mechanism.
Colorectal Neoplasms ; genetics ; HCT116 Cells ; Humans ; MicroRNAs ; genetics ; PTEN Phosphohydrolase ; RNA, Messenger

To investigate the cellular target selectivity of small molecules targeting thioredoxin reductase 1, we reported the construction and functional research of a stable TrxR1 gene (encode thioredoxin reductase 1) knockout HCT-116 cell line. We designed and selected TrxR1 knockout sites according to the TrxR1 gene sequence and CRISPR/Cas9 target designing principles. SgRNA oligos based on the selected TrxR1 knockout sites were obtained. Next, we constructed knockout plasmid by cloning the sgRNA into the pCasCMV-Puro-U6 vector. After transfection of the plasmid into HCT-116 cells, TrxR1 knockout HCT-116 cells were selected using puromycin resistance. The TrxR1 knockout efficiency was identified and verified by DNA sequencing, immunoblotting, TRFS-green fluorescent probe, and cellular TrxR1 enzyme activity detection. Finally, the correlation between TrxR1 expression and cellular effects of drugs specifically targeting TrxR1 was investigated by CCK-8 assay. The results demonstrated that the knockout plasmid expressing the sgRNA effectively knocked-out TrxR1 gene within HCT-116 cells, and no expression of TrxR1 protein could be observed in stable TrxR1 knockout HCT-116 (HCT116-TrxR1-KO) cells. The TrxR1-targeting inhibitor auranofin did not show any inhibitory activity against either cellular TrxR1 enzyme activity or cell proliferation. Based on these results, we conclude that a stable TrxR1 gene knockout HCT-116 cell line was obtained through CRISPR/Cas9 techniques, which may facilitate investigating the role of TrxR1 in various diseases.
CRISPR-Cas Systems/genetics* ; Gene Editing ; Gene Knockout Techniques ; HCT116 Cells ; Humans ; RNA, Guide/metabolism*

PURPOSE: To determine CD133+ cells defined as cancer stem cells (CSCs) in colon cancer, we examined whether CD133+ clones in HCT116 demonstrate known features of CSCs like sphere-forming ability, chemodrug-resistance, and metastatic potential. METHODS: Magnetic cell isolation and cell separation demonstrated that <1% of HCT116 cells expressed CD133, with the remaining cells being CD133- clones. In colon cancer cells, radioresistance is also considered a CSC characteristic. We performed clonogenic assay using 0.4 Gy γ-irradiation. RESULTS: Interestingly, there were no differences between HCT116 parental and HCT116 CD133+ clones when the cells comprised 0.5% of the total cells, and CD133- clone demonstrated radiosensitive changes compared with parental and CD133+ clones. Comparing gene expression profiles between sphere-forming and nonforming culture conditions of HCT116 subclones by whole RNA sequencing failed to obtain specific genes expressed in CD133+ clones. CONCLUSION: Despite no differences of gene expression profiles in monolayer attached culture conditions of each clone, sphere-forming conditions of whole HCT116 subclones, parental, CD133+, and CD133- increased 1,761 coding genes and downregulated 1,384 genes related to CSCs self-renewal and survival. Thus, spheroid cultures of HCT116 cells could be useful to expand colorectal CSCs rather than clonal expansion depending on CD133 expressions.
Cell Separation ; Clinical Coding ; Clone Cells* ; Colonic Neoplasms ; HCT116 Cells ; Humans ; Neoplastic Stem Cells ; Parents ; RNA* ; Sequence Analysis, RNA* ; Transcriptome

OBJECTIVETo analyze the molecular coining of a fragile site-associated gene.

METHODSGenomic Chinese hamster ovary (CHO) DNA library was constructed using high molecular weight CHO DNA partially digested with MboI restriction enzyme from cultured CHO cells. Screening of genomic DNA library followed the established procedures. Genomic CHO in the positive clones was sequenced. Appropriate primers were designed for the reverse transcriptase-polymerase chain reactions (RT-PCR). The RT-PCR products were cloned into a pCRII TOPO vector and confirmed by DNA sequencing. Antibodies were prepared using synthetic peptides as antigens by immunizing the rabbits. Immunohistochemical analyses were performed to evaluate the expression of the novel gene in different tissues.

RESULTSTo investigate the molecular mechanism underlying the initial events of mdr1a amplification, we cloned 1q31 fragile site DNA. Strikingly, we found that this fragile site contained a novel gene which was designated as a fragile site-associated (FSA) gene. FSA encoded an unusually large mRNA of approximately16 kb. Full-length human FSA cDNA was cloned. FSA mRNA was expressed in many cultured cells and tissue types. Immunohistochemical analyses also revealed an expression pattern of the encoded proteins in postmitotic, well-differentiated epithelial compartments of many organs, including colon, mammary glands, ovary, prostate, and bladder.

CONCLUSIONFSA plays an important role in regulating mammalian epithelial cell growth and differentiation.

Animals ; CHO Cells ; Cell Line ; Chromosome Fragile Sites ; genetics ; Cloning, Molecular ; Cricetinae ; Cricetulus ; HCT116 Cells ; HT29 Cells ; Humans

Sur8, a scaffold protein of the Ras pathway, interacts with Ras and Raf and modulates the Ras-extracellular signal-regulated kinase (ERK) pathway. Here we show that Sur8 is overexpressed in established human colorectal cancer (CRC) cell lines and CRC patient tissues. Moreover, Sur8 expression is increased during liver metastasis in CRC patients. Sur8 knockdown decreases ERK and Akt activities in CRC cell lines, regardless of their K-Ras, B-Raf or PI3K mutation status. Overexpression or knockdown of Sur8 increases or decreases, respectively, the proliferation or transformation of CRC cell lines. Sur8 knockdown attenuates the migration and invasion of HCT116 CRC cells. Subcutaneous or orthotopic injection of HCT116 cells harboring a doxycycline (Dox)-mediated Sur8 knockdown system in nude mice resulted in decreased tumorigenic potential and inhibited the liver metastatic potential of HCT116 cells. Taken together, our data support the role of Sur8 as a promoter of tumorigenesis and liver metastasis in CRC through its modulation of the Ras-ERK and PI3K-Akt signaling pathways.
Animals ; Carcinogenesis* ; Cell Line ; Colorectal Neoplasms* ; Doxycycline ; HCT116 Cells ; Humans ; Liver ; Mice ; Mice, Nude ; Neoplasm Metastasis* ; Phosphotransferases

PURPOSE: Livin is associated with drug response in several cancers. The aim of this study was to investigate the effect of silencing the livin gene expression on anticancer drug response in colorectal cancer. METHODS: siRNA was transfected at different concentrations (0, 10, and 30nM) into HCT116 cells, then cells were treated with either 5-fluorouracil (FU)/leucovorin (LV) or oxaliplatin (L-OHP)/5-FU/LV. Cellular viability and apoptosis were evaluated following silencing of livin gene expression combined with treatment with anticancer drugs. RESULTS: Livin gene expression was effectively suppressed by 30nM siRNA compared with control and 10nM siRNA. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay showed that proliferation was effectively inhibited in cells treated with a combination of both siRNA and an anticancer drug, compared to cells treated with siRNA-Livin or anticancer drug alone. In particular, the combination of 30nM siRNA and L-OHP/5-FU/LV resulted in a 93.8% and 91.4% decrease, compared to untreated control or L-OHP/5-FU/LV alone, respectively. Cellular proliferation was most effectively suppressed by a combination of 30nM of siRNA and L-OHP/5-FU/LV compared to other combinations. CONCLUSION: siRNA-mediated down-regulation of livin gene expression could significantly suppress colon cancer growth and enhance the cytotoxic effects of anticancer drugs such as 5-FU and L-OHP. The results of this study suggest that silencing livin gene expression in combination with treatment with anticancer drugs might be a novel cancer therapy for colorectal cancer.
Apoptosis ; Cell Proliferation ; Colon* ; Colonic Neoplasms* ; Colorectal Neoplasms ; Down-Regulation ; Fluorouracil ; Gene Expression ; HCT116 Cells ; RNA, Small Interfering