Limitless reproductive potential is one of the hallmarks of cancer cells1. This ability is accomplished by maintaining telomeres, which erosion otherwise causes cellular senescence or death. Human cancer cells often maintain shorter telomeres than do cells in surrounding normal tissues2-5. While most cancer cells activate telomerase, which can elongate telomeres6, it remains elusive why cancer cells keep telomeres short. Here we show that forced elongation of telomeres in cancer cells promotes their differentiation in a tumor microenvironment in vivo. We elongated telomeres of human prostate cancer PC-3 cells, which possess short telomeres7, by enhancing their telomerase activity. The resulting cells with long telomeres retain an ability to form tumors in a mouse xenograft model. Strikingly, these tumors exhibit many duct-like structures and reduced N-cadherin expression, reminiscent of well-differentiated adenocarcinoma. These phenotypic changes are caused by telomere elongation per se but not enhanced telomerase activity. Gene expression profiling revealed that telomere elongation correlates with inhibition of cell-cycle processes. Together, our results suggest a functional contribution of short telomeres to tumor malignancy by regulating cancer cell differentiation.
Telomere length influences cancer cell differentiation in vivo.
Cell line
View SamplesTelomere erosion causes cell mortality, suggesting that longer telomeres allow greater number of cell division. In telomerase-positive human cancer cells, however, telomeres are often kept shorter than the surrounding normal tissues. Recently, we have shown that telomere elongation in cancer cells represses innate immune genes and promotes their differentiation in vivo. This implies that short telomeres contribute to cancer malignancy, but it is unclear how such genetic repression is caused by long telomeres. Here we report that telomeric repeat-containing RNA (TERRA) induces genome-wide alteration of gene expression in telomere-elongated cancer cells in vivo. Using three different cell lines, we found that G4 forming oligonucleotide repressed innate immune genes in vivo 3D culture conditions. Most of the suppressed genes belonged to innate immune system categories and were upregulated in various cancers. We propose that TERRA G4 counteracts cancer malignancy through suppression of innate immune genes.
Telomeric repeat-containing RNA/G-quadruplex-forming sequences cause genome-wide alteration of gene expression in human cancer cells in vivo.
Cell line, Treatment
View SamplesTelomere erosion causes cell mortality, suggesting that longer telomeres allow greater number of cell division. In telomerase-positive human cancer cells, however, telomeres are often kept shorter than the surrounding normal tissues. Recently, we have shown that telomere elongation in cancer cells represses innate immune genes and promotes their differentiation in vivo. This implies that short telomeres contribute to cancer malignancy, but it is unclear how such genetic repression is caused by long telomeres. Here we report that telomeric repeat-containing RNA (TERRA) induces genome-wide alteration of gene expression in telomere-elongated cancer cells in vivo. Using three different cell lines, we found that telomere elongation upregulates TERRA and downregulates innate immune genes in vivo xenograft tumors. Most of the suppressed genes belonged to innate immune system categories and were upregulated in various cancers. We propose that TERRA G4 counteracts cancer malignancy through suppression of innate immune genes.
Telomeric repeat-containing RNA/G-quadruplex-forming sequences cause genome-wide alteration of gene expression in human cancer cells in vivo.
Disease, Cell line
View SamplesLimitless reproductive potential is one of the hallmarks of cancer cells1. This ability is accomplished by maintaining telomeres, which erosion otherwise causes cellular senescence or death. Human cancer cells often maintain shorter telomeres than do cells in surrounding normal tissues2-5. While most cancer cells activate telomerase, which can elongate telomeres6, it remains elusive why cancer cells keep telomeres short. Here we show that forced elongation of telomeres in cancer cells promotes their differentiation in a tumor microenvironment in vivo. We elongated telomeres of human prostate cancer PC-3 cells, which possess short telomeres7, by enhancing their telomerase activity. The resulting cells with long telomeres retain an ability to form tumors in a mouse xenograft model. Strikingly, these tumors exhibit many duct-like structures and reduced N-cadherin expression, reminiscent of well-differentiated adenocarcinoma. These phenotypic changes are caused by telomere elongation per se but not enhanced telomerase activity. Gene expression profiling revealed that telomere elongation correlates with inhibition of cell-cycle processes. Together, our results suggest a functional contribution of short telomeres to tumor malignancy by regulating cancer cell differentiation.
Telomere length influences cancer cell differentiation in vivo.
Cell line
View SamplesAPC inactivation is the early process in the tumorigenesis of colorectal cancer. We established organoid cultures from intestines of genetically modifeid mice harboring Apcfl/fl and R26CreERT2 allele
No associated publication
Specimen part
View SamplesAPC inactivation is the early process in the tumorigenesis of colorectal cancer. We established organoid cultures from intestines of genetically modifeid mice harboring Apcfl/fl, Tacc3wt/wt or Apcfl/fl, Tacc3fl/fll and R26CreERT2 allele
Suppression of intestinal tumors by targeting the mitotic spindle of intestinal stem cells.
Specimen part
View SamplesTumors consist of heterogeneous cell population, containing cancer cell subpopulations with anticancer drug-resistant property, called “persister” cells. To reveal the character of the persister cells, we analyzed gene expression profile of patient-derived gastric cells and residual cancer cells after treatment with 5-FU or SN38, an active metabolite of irinotecan. In our study, we identified ALDH1A3 as a marker and a cell proliferation factor of persister cells. To examine molecular pathways regulated by ALDH1A3, we analyzed gene expression profile of patient-derived gastric JSC15-3 in which ALDH1A3 was knocked down by using shRNAs.
ALDH1A3-mTOR axis as a therapeutic target for anticancer drug-tolerant persister cells in gastric cancer.
Specimen part, Cell line, Treatment
View SamplesA capability to proliferate under the three-dimensional (3D) conditions is a characteristic property of cancer. Therefore, factors that regulate the 3D growth are considered rational targets for cancer therapy. We analyzed gene expression profile of human prostate cancer PC3 cells which were cultured in normal 2D conditions or in spheroid culture conditions (3D). The analysis suggested that the sheroid conditions would mimic a part of tumor-like 3D conditions. In addition, we analyzed genes regulated by TRIB1, a candidate oncogene in PC3 cells by comparing the gene expression profiles between control (shGFP)-treated and TRIB1 shRNA- (shTRIB1-1 and shTRIB1-2) treated cells. Our analysis identified a subset of genes that are downstream of TRIB1 in prostate cancer cells.
No associated publication
Cell line
View SamplesWnt/-catenin signaling is activated in colorectal cancer (CRC) and is involved in CRC growth. Tankyrase, a poly(ADP-ribose) polymerase family member, destabilizes Axin and positively regulates the Wnt/-catenin signaling. Tankyrase inhibitors efficiently suppress CRC cell proliferation. We established 320-IWR cells, which showed resistance to tankyrase inhibitor IWR-1, from human CRC COLO-320DM cells. We analyzed gene expression profile of 320-IWR cells (320IWR_1,_2) and parental COLO-320DM cells (COLO320_1,_2).
No associated publication
Specimen part, Cell line
View SamplesTankyrase enhances beta-catenin signaling via PARsylation and subsequent degradation of Axin, a negative regulator of beta-catenin. Tankyrase inhibitors stabilize Axin and suppress beta-catenin signaling. We developed a novel tankyrase inhibitor, RK-287107.
RK-287107, a potent and specific tankyrase inhibitor, blocks colorectal cancer cell growth in a preclinical model.
Specimen part, Treatment
View Samples