DCLK1 facilitates intestinal tumor growth via enhancing pluripotency and epithelial mesenchymal transition

Commensal-infected macrophages induce dedifferentiation and reprogramming of epithelial cells during colorectal carcinogenesis

The colonic microbiome contributes to the initiation of colorectal cancer through poorly characterized mechanisms. We have shown that commensal-polarized macrophages induce gene mutation, chromosomal instability, and endogenous transformation through microbiome-induced bystander effects (MIBE). In this study we show that MIBE activates Wnt/β-catenin signaling and pluripotent transcription factors associated with dedifferentiation, reprogramming, and the development of colorectal cancer stem cells (CSCs). Exposure of murine primary colon epithelial cells (YAMC) to Enterococcus faecalis-infected macrophages increased Wnt3α expression while suppressing Wnt inhibitor factor 1 (Wif1). Wnt/β-catenin activation was confirmed by increased active β-catenin and Tcf4. in vivo, active β-catenin was evident in colon biopsies from E. faecalis-colonized Il10 knockout mice compared to sham-colonized mice. This effect was mediated, in part, by 4-hydroxy-2-nonenal and tumor necrosis factor α. MIBE also activated pluripotent transcription factors c-Myc, Klf4, Oct4, and Sox2 in YAMC cells and colons from E. faecalis-colonized Il10 knockout mice. These transcription factors are associated with cellular reprogramming, dedifferentiation, and induction of colorectal CSC progenitors. In support of this was an increase in the expression of Dclk1 and CD44, two colorectal CSC markers, in YAMC cells that were exposed to MIBE. Finally, compared to normal colon biopsies and hyperplastic polyps, DCLK1 expression increased in human tubular adenomas and invasive colorectal cancers. Blocking β-catenin/TCF4 signaling using FH535 and CTNNB1-specific small interfering RNA decreased DCLK1 expression in HCT116 human colon cancer cells. These findings provide mechanism for microbiome-induced colorectal cancer and identify new potential targets for colorectal cancer prevention.

Doublecortin and CaM kinase-like-1 as an independent prognostic factor in patients with resected pancreatic carcinoma

AIM

To elucidate the effect of expression of doublecortin and CaM kinase-like-1 (DCLK1) in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

Tumor specimens were obtained from 136 patients with pancreatic cancer who had undergone resection without preoperative therapy between January 2000 and December 2013 at the Department of Surgical Oncology, Osaka City University. The resected specimens were analyzed for associations with clinicopathological data, including DCLK1 expression, epithelial mesenchymal transition (EMT) marker expression, and cancer stem cell (CSC) marker expression. Univariate and multivariate survival analyses were performed and we assessed the association between DCLK1 expression and clinicopathological factors, including the EMT marker and CSC marker.

RESULTS

In total, 48.5% (66/136) of the pancreatic cancer samples were positive for DCLK1. Patients with DCLK1-positive tumors had significantly shorter survival times than those with DCLK1-negative tumors (median, 18.7 mo vs 49.5 mo, respectively; P < 0.0001). Positive DCLK1 expression correlated with histological grade (P = 0.0290), preoperative CA19-9 level (P = 0.0060), epithelial cell adhesion molecule (EpCAM) expression (P = 0.0235), and the triple-positive expression of CD44/CD24/EpCAM (P = 0.0139). On univariate survival analysis, five factors were significantly associated with worse overall survival: histological grade of G2 to G4 (P = 0.0091), high preoperative serum SPan-1 level (P = 0.0034), R1/2 (P < 0.0001), positive expression of DCLK1 (P < 0.0001) or CD44 (P = 0.0245). On multivariate survival analysis, R1/2 [odds ratio (OR) = 2.019, 95% confidence interval (CI): 1.380-2.933; P = 0.0004] and positive DCLK1 expression (OR = 1.848, 95%CI: 1.2854-2.661; P = 0.0009) were independent prognostic factors.

CONCLUSION

DCLK1 expression was found to be an independent prognostic factor and it may play a crucial prognostic role by promoting acquisition of stemness.

Roles of Wnt Target Genes in the Journey of Cancer Stem Cells

The importance of Wnt/β-catenin signaling in cancer stem cells (CSCs) has been acknowledged; however, the mechanism through which it regulates the biological function of CSCs and promotes cancer progression remains elusive. Hence, to understand the intricate mechanism by which Wnt controls stemness, the specific downstream target genes of Wnt were established by analyzing the genetic signatures of multiple types of metastatic cancers based on gene set enrichment. By focusing on the molecular function of Wnt target genes, the biological roles of Wnt were interpreted in terms of CSC dynamics from initiation to metastasis. Wnt signaling participates in cancer initiation by generating CSCs from normal stem cells or non-CSCs and augmenting persistent growth at the primary region, which is resistant to anti-cancer therapy. Moreover, it assists CSCs in invading nearby tissues and in entering the blood stream, during which the negative feedback of the Wnt signaling pathway maintains CSCs in a dormant state that is suitable for survival. When CSCs arrive at distant organs, another burst of Wnt signaling induces CSCs to succeed in re-initiation and colonization. This comprehensive understanding of Wnt target genes provides a plausible explanation for how Wnt allows CSCs variation during cancer progression.

Microbiome-driven carcinogenesis in colorectal cancer: Models and mechanisms

Colorectal cancer (CRC) is a leading cause of cancer death and archetype for cancer as a genetic disease. However, the mechanisms for genetic change and their interactions with environmental risk factors have been difficult to unravel. New hypotheses, models, and methods are being used to investigate a complex web of risk factors that includes the intestinal microbiome. Recent research has clarified how the microbiome can generate genomic change in CRC. Several phenotypes among a small group of selected commensals have helped us better understand how mutations and chromosomal instability (CIN) are induced in CRC (e.g., toxin production, metabolite formation, radical generation, and immune modulation leading to a bystander effect). This review discusses recent hypotheses, models, and mechanisms by which the intestinal microbiome contributes to the initiation and progression of sporadic and colitis-associated forms of CRC. Overall, it appears the microbiome can initiate and/or promote CRC at all stages of tumorigenesis by acting as an inducer of DNA damage and CIN, regulating cell growth and death, generating epigenetic changes, and modulating host immune responses. Understanding how the microbiome interacts with other risk factors to define colorectal carcinogenesis will ultimately lead to more accurate risk prediction. A deeper understanding of CRC etiology will also help identify new targets for prevention and treatment and help accelerate the decline in mortality for this common cancer.

Dclk1, a tumor stem cell marker, regulates pro-survival signaling and self-renewal of intestinal tumor cells

BACKGROUND

More than 80% of intestinal neoplasia is associated with the adenomatous polyposis coli (APC) mutation. Doublecortin-like kinase 1 (Dclk1), a kinase protein, is overexpressed in colorectal cancer and specifically marks tumor stem cells (TSCs) that self-renew and increased the tumor progeny in Apc ^Min/+ mice. However, the role of Dclk1 expression and its contribution to regulating pro-survival signaling for tumor progression in Apc mutant cancer is poorly understood.

METHODS

We analyzed DCLK1 and pro-survival signaling gene expression datasets of 329 specimens from TCGA Colon Adenocarcinoma Cancer Data. The network of DCLK1 and pro-survival signaling was analyzed utilizing the GeneMANIA database. We examined the expression levels of Dclk1 and other stem cell-associated markers, pro-survival signaling pathways, cell self-renewal in the isolated intestinal epithelial cells of Apc ^Min/+ mice with high-grade dysplasia and adenocarcinoma. To determine the functional role of Dclk1 for tumor progression, we knocked down Dclk1 and determined the pro-survival signaling pathways and stemness. We used siRNA technology to gene silence pro-survival signaling in colon cancer cells in vitro. We utilized FACS, IHC, western blot, RT-PCR, and clonogenic (self-renewal) assays.

RESULTS

We found a correlation between DCLK1 and pro-survival signaling expression. The expression of Dclk1 and stem cell-associated markers Lgr5, Bmi1, and Musashi1 were significantly higher in the intestinal epithelial cells of Apc ^Min/+ mice than in wild-type controls. Intestinal epithelial cells of Apc ^Min/+ mice showed increased expression of pro-survival signaling, pluripotency and self-renewal ability. Furthermore, the enteroids formed from the intestinal Dclk1⁺ cells of Apc ^Min/+ mice display higher pluripotency and pro-survival signaling. Dclk1 knockdown in Apc ^Min/+ mice attenuates intestinal adenomas and adenocarcinoma, and decreases pro-survival signaling and self-renewal. Knocking down RELA and NOTCH1 pro-survival signaling and DCLK1 in HT29 and DLD1 colon cancer cells in vitro reduced the tumor cells' ability to self-renew and survive.

CONCLUSION

Our results indicate that Dclk1 is essential in advancing intestinal tumorigenesis. Knocking down Dclk1 decreases tumor stemness and progression and is thus predicted to regulate pro-survival signaling and tumor cell pluripotency. This study provides a strong rationale to target Dclk1 as a treatment strategy for colorectal cancer.

Doublecortin-like kinase 1 expression associates with breast cancer with neuroendocrine differentiation

Doublecortin-like kinase 1 (DCLK1), a microtubule associated kinase, has recently been proposed to be a putative marker for stemness and adverse prognosis in gastrointestinal cancers. However, it is not clear whether the protein also plays similar roles in breast cancer. Here, the expression of DCLK1 was analyzed in a large cohort of invasive breast cancers (IBC) by immunohistochemistry. DCKL1 was associated with favorable clinico-pathologic features, namely lower histologic grade, absence of lymphovascular invasion, fibrotic focus, necrosis and lower pN stage (p≤0.045). Additionally, independent significant correlations were found with estrogen receptor and neuroendocrine markers (p ≤0.019), implicating its relationship with IBC with neuroendocrine differentiation (IBC-NED). In the current cohort, IBC-NED showed worse outcome than luminal cancers without NED (hazard ratio=1.756, p=0.041). Interestingly, within the IBC-NED group, DCLK1 was found to be a good prognostic factor (hazard ratio =0.288, p=0.011). These findings were in contrast to those in gastrointestinal cancers, suggesting different functional roles of DCLK1 in different types of cancers. In clinical practice, NED is not routinely assessed; thus IBC-NED are not well studied. Its poor outcome and significant heterogeneity warrants more attention. DCLK1 expression could aid in the prognostication and management of this special cancer subtype.

Dclk1+ small intestinal epithelial tuft cells display the hallmarks of quiescence and self-renewal

To date, no discrete genetic signature has been defined for isolated Dclk1+ tuft cells within the small intestine. Furthermore, recent reports on the functional significance of Dclk1+ cells in the small intestine have been inconsistent. These cells have been proposed to be fully differentiated cells, reserve stem cells, and tumor stem cells. In order to elucidate the potential function of Dclk1+ cells, we FACS-sorted Dclk1+ cells from mouse small intestinal epithelium using transgenic mice expressing YFP under the control of the Dclk1 promoter (Dclk1-CreER;Rosa26-YFP). Analysis of sorted YFP+ cells demonstrated marked enrichment (~6000 fold) for Dclk1 mRNA compared with YFP- cells. Dclk1+ population display ~6 fold enrichment for the putative quiescent stem cell marker Bmi1. We observed significantly greater expression of pluripotency genes, pro-survival genes, and quiescence markers in the Dclk1+ population. A significant increase in self-renewal capability (14-fold) was observed in in vitro isolated Dclk1+ cells. The unique genetic report presented in this manuscript suggests that Dclk1+ cells may maintain quiescence, pluripotency, and metabolic activity for survival/longevity. Functionally, these reserve characteristics manifest in vitro, with Dclk1+ cells exhibiting greater ability to self-renew. These findings indicate that quiescent stem-like functionality is a feature of Dclk1-expressing tuft cells.

Inflammatory and oncogenic roles of a tumor stem cell marker doublecortin-like kinase (DCLK1) in virus-induced chronic liver diseases

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related mortality worldwide. We previously showed that a tumor/cancer stem cell (CSC) marker, doublecortin-like kinase (DCLK1) positively regulates hepatitis C virus (HCV) replication, and promotes tumor growth in colon and pancreas. Here, we employed transcriptome analysis, RNA interference, tumor xenografts, patient's liver tissues and hepatospheroids to investigate DCLK1-regulated inflammation and tumorigenesis in the liver. Our studies unveiled novel DCLK1-controlled feed-forward signaling cascades involving calprotectin subunit S100A9 and NFκB activation as a driver of inflammation. Validation of transcriptome data suggests that DCLK1 co-expression with HCV induces BRM/SMARCA2 of SW1/SNF1 chromatin remodeling complexes. Frequently observed lymphoid aggregates including hepatic epithelial and stromal cells of internodular septa extensively express DCLK1 and S100A9. The DCLK1 overexpression also correlates with increased levels of S100A9, c-Myc, and BRM levels in HCV/HBV-positive patients with cirrhosis and HCC. DCLK1 silencing inhibits S100A9 expression and hepatoma cell migration. Normal human hepatocytes (NHH)-derived spheroids exhibit CSC properties. These results provide new insights into the molecular mechanism of the hepatitis B/C-virus induced liver inflammation and tumorigenesis via DCLK1-controlled networks. Thus, DCLK1 appears to be a novel therapeutic target for the treatment of inflammatory diseases and HCC.

Survival of Patients with Gastrointestinal Cancers Can Be Predicted by a Surrogate microRNA Signature for Cancer Stem-like Cells Marked by DCLK1 Kinase

Doublecortin-like kinase 1 (DCLK1) is a gastrointestinal (GI) tuft cell kinase that has been investigated as a biomarker of cancer stem-like cells in colon and pancreatic cancers. However, its utility as a biomarker may be limited in principle by signal instability and dilution in heterogeneous tumors, where the proliferation of diverse tumor cell lineages obscures the direct measurement of DCLK1 activity. To address this issue, we explored the definition of a miRNA signature as a surrogate biomarker for DCLK1 in cancer stem-like cells. Utilizing RNA/miRNA-sequencing datasets from the Cancer Genome Atlas, we identified a surrogate 15-miRNA expression signature for DCLK1 activity across several GI cancers, including colon, pancreatic, and stomach cancers. Notably, Cox regression and Kaplan-Meier analysis demonstrated that this signature could predict the survival of patients with these cancers. Moreover, we identified patient subgroups that predicted the clinical utility of this DCLK1 surrogate biomarker. Our findings greatly strengthen the clinical significance for DCLK1 expression across GI cancers. Further, they provide an initial guidepost toward the development of improved prognostic biomarkers or companion biomarkers for DCLK1-targeted therapies to eradicate cancer stem-like cells in these malignancies. Cancer Res; 76(14); 4090-9. ©2016 AACR.

Characterizing the molecular features of ERG-positive tumors in primary and castration resistant prostate cancer

BACKGROUND

The TMPRSS2-ERG gene fusion is detected in approximately half of primary prostate cancers (PCa) yet the prognostic significance remains unclear. We hypothesized that ERG promotes the expression of common genes in primary PCa and metastatic castration-resistant PCa (CRPC), with the objective of identifying ERG-associated pathways, which may promote the transition from primary PCa to CRPC.

METHODS

We constructed tissue microarrays (TMA) from 127 radical prostatectomy specimens, 20 LuCaP patient-derived xenografts (PDX), and 152 CRPC metastases obtained immediately at time of death. Nuclear ERG was assessed by immunohistochemistry (IHC). To characterize the molecular features of ERG-expressing PCa, a subset of IHC confirmed ERG+ or ERG- specimens including 11 radical prostatectomies, 20 LuCaP PDXs, and 45 CRPC metastases underwent gene expression analysis. Genes were ranked based on expression in primary PCa and CRPC. Common genes of interest were targeted for IHC analysis and expression compared with biochemical recurrence (BCR) status.

RESULTS

IHC revealed that 43% of primary PCa, 35% of the LuCaP PDXs, and 18% of the CRPC metastases were ERG+ (12 of 48 patients [25%] had at least one ERG+ metastasis). Based on gene expression data and previous literature, two proteins involved in calcium signaling (NCALD, CACNA1D), a protein involved in inflammation (HLA-DMB), CD3 positive immune cells, and a novel ERG-associated protein, DCLK1 were evaluated in primary PCa and CRPC metastases. In ERG+ primary PCa, a weak association was seen with NCALD and CACNA1D protein expression. HLA-DMB association with ERG was decreased and CD3 cell number association with ERG was changed from positive to negative in CRPC metastases compared to primary PCa. DCLK1 was upregulated at the protein level in unpaired ERG+ primary PCa and CRPC metastases (P = 0.0013 and P < 0.0001, respectively). In primary PCa, ERG status or expression of targeted proteins was not associated with BCR-free survival. However, for primary PCa, ERG+DCLK1+ patients exhibited shorter time to BCR (P = 0.06) compared with ERG+DCLK1- patients.

CONCLUSIONS

This study examined ERG expression in primary PCa and CRPC. We have identified altered levels of inflammatory mediators associated with ERG expression. We determined expression of DCLK1 correlates with ERG expression and may play a role in primary PCa progression to metastatic CPRC. Prostate 76:810-822, 2016. © 2016 Wiley Periodicals, Inc.

miR-613 inhibits the growth and invasiveness of human hepatocellular carcinoma via targeting DCLK1

microRNAs (miRNAs) play key regulatory roles in various biological processes. In this study, we aimed to determine the expression and biological roles of miR-613 in hepatocellular carcinoma (HCC). Compared with non-cancerous liver tissues, miR-613 was significantly downregulated in HCC tissues. Ectopic expression of miR-613 significantly suppressed the proliferation and invasion of Hep3B and SMMC-7721 HCC cells. Bioinformatic and luciferase reporter analysis identified doublecortin-like kinase 1 (DCLK1) as a direct target of miR-613. Overexpression of miR-613 inhibited the expression of DCLK1 in HCC cells. There was a significant inverse correlation between miR-613 and DCLK1 protein expression in HCC samples. Small interfering RNA-mediated silencing of DCLK1 phenocopied the suppressive effects of miR-613 in HCC cells. Rescue experiments demonstrated that co-transfection of DCLK1 lacking the 3'-untranslated region partially prevented miR-613-induced suppression of HCC cell proliferation and invasion. In vivo studies confirmed that miR-613 overexpression retarded the growth of Hep3B xenograft tumors in nude mice, coupled with a reduction in the percentage of Ki67-positive tumor cells and DCLK1 protein expression. In conclusion, we provide first evidence for the suppressive activity of miR-613 in HCC, which is causally linked to targeting of DCLK1. Restoration of miR-613 may provide a potential therapeutic strategy for HCC.

Regulatory Roles of Dclk1 in Epithelial Mesenchymal Transition and Cancer Stem Cells

The identification of functionally relevant subpopulations of therapy-resistant cancer cells is a challenge. These cells, intrinsically resistant to conventional therapy, can cause recurrence. Evidence has suggested that therapy-resistant cancer cells are likely epithelial–mesenchymal transition (EMT) cells and/or stem-like cells called cancer stem cells (CSCs). EMT, a normal embryological process that converts epithelial cells into mesenchymal cells, is frequently activated during cancer development and progression. CSCs are a small subpopulation of cancer cells within a tumor mass that have the ability to self-renew and maintain tumor-initiating capacity by giving rise to heterogeneous lineages of cancer cells that comprise the whole tumor. Although the origin of CSCs and EMT cells remains to be fully explored, a growing body of evidence has indicated that the biology of EMT and CSCs is strongly linked. Doublecortin-like kinase 1 (DCLK1), a cancer stem cell marker, is functionally involved in maintaining cancer stemness and the process of EMT important for cancer initiation, cancer metastasis, and secondary tumor formation. Therefore, targeting these cells may provide new strategies to overcome tumor heterogeneity, therapeutic resistance, and cancer relapse. In this review, we will provide a potential mechanistic link between EMT induction and the emergence of CSCs for the origin and progression of cancer. We will highlight the functional activity of DCLK1 in supporting EMT and cancer cell self-renewal, which will lead us to a better understanding of DCLK1 expression in cancer development and progression, and help us to develop targeted therapies for effective cancer treatment.

DCLK1 is a broadly dysregulated target against epithelial-mesenchymal transition, focal adhesion, and stemness in clear cell renal carcinoma

Renal clear cell carcinoma (RCC) is the most common type of kidney cancer and the 8^th most common cancer overall in the US. RCC survival rates drop precipitously with regional and distant spread and recent studies have demonstrated that RCC presents an epithelial-mesenchymal transition (EMT) phenotype linked to increased recurrence and decreased survival. EMT is a key characteristic of tumor stem cells (TSCs) along with chemo-resistance and radio-resistance, which are also phenotypic of RCC. Targeting these factors is key to increasing the survival of RCC patients. Doublecortin-like kinase 1 (DCLK1) marks TSCs in pancreatic and colorectal cancer and regulates EMT and stemness. Analysis of the Cancer Genome Atlas' RCC dataset revealed that DCLK1 is overexpressed and dysregulated on the mRNA and epigenetic level in more than 93% of RCC tumors relative to adjacent normal tissue. Immunohistochemistry using α-DCLK1 antibody confirmed overexpression and demonstrated a major increase in immunoreactivity in stage II-III tumors compared to normal kidney and stage I tumors. Small-interfering RNA (siRNA) mediated knockdown of DCLK1 resulted in decreased expression of EMT and pluripotency factors and significantly reduced invasion, migration, focal adhesion, drug-resistance, and clonogenic capacity. These findings suggest that DCLK1 is a novel, overexpressed factor in RCC progression that may be targeted to suppress EMT, metastasis, and stemness in early-stage and advanced RCC to increase patient survival. Moreover, the possibility that DCLK1 may mark a population of tumor stem-like cells in RCC should be further investigated in light of these findings.

Plasma DCLK1 is a marker of hepatocellular carcinoma (HCC): Targeting DCLK1 prevents HCC tumor xenograft growth via a microRNA-dependent mechanism

Tumor stem cell marker Doublecortin-like kinase1 (DCLK1) is upregulated in several solid tumors. The role of DCLK1 in hepatocellular carcinoma (HCC) is unclear. We immunostained tissues from human livers with HCC, cirrhosis controls (CC), and non-cirrhosis controls (NCC) for DCLK1. Western blot and ELISA analyses for DCLK1 were performed with stored plasma samples. We observed increased immunoreactive DCLK1 in epithelia and stroma in HCC and CCs compared with NCCs, and observed a marked increase in plasma DCLK1 from patients with HCC compared with CC and NCC. Analysis of the Cancer Genome Atlas' HCC dataset revealed that DCLK1 is overexpressed in HCC tumors relative to adjacent normal tissues. High DCLK1-expressing cells had more epithelial-mesenchymal transition (EMT). Various tumor suppressor miRNAs were also downregulated in HCC tumors. We evaluated the effects of DCLK1 knockdown on Huh7.5-derived tumor xenograft growth. This was associated with growth arrest and a marked downregulation of cMYC, and EMT transcription factors ZEB1, ZEB2, SNAIL, and SLUG via let-7a and miR-200 miRNA-dependent mechanisms. Furthermore, upregulation of miR-143/145, a corresponding decrease in pluripotency factors OCT4, NANOG, KLF4, and LIN28, and a reduction of let-7a, miR-143/145, and miR-200-specific luciferase activity was observed. These findings suggest that the detection of elevated plasma DCLK1 may provide a cost-effective, less invasive tool for confirmation of clinical signs of cirrhosis, and a potential companion diagnostic marker for patients with cirrhosis and HCC. Our results support evaluating DCLK1 as a biomarker for detection and as a therapeutic target for eradicating HCC.

Epigenetic changes and alternate promoter usage by human colon cancers for expressing DCLK1-isoforms: Clinical Implications

DCLK1 specifically marks colon/pancreatic cancers in mice, and is expressed by human colon adenocarcinomas (hCRCs). Down-regulation of DCLK1 results in loss of cancer-stem-cells (CSCs), and inhibits spheroidal/xenograft growths from hCRC-cells. The 5'-promoter of DCLK1-gene is reportedly hypermethylated in hCRCs, resulting in loss of expression of DCLK1-transcripts, originating from 5'(α)-promoter (termed DCLK1-L, in here). However, in mouse colon-tumors, 5'-promoter of DCLK1-gene remains unchanged, and DCLK1-L, originating from 5'(α)-promoter, is expressed. We hypothesized that elevated levels of DCLK1-protein in hCRC-cells, may be transcribed/translated from an alternate-promoter. Several in silico and molecular biology approaches were used to test our hypothesis. We report for the first time that majority of hCRCs express short-transcripts of DCLK1 (termed DCLK1-S, in here) from an alternate β-promoter in IntronV of the gene, while normal-colons mainly express DCLK1-L from 5'(α)-promoter. We additionally report an important role of β-catenin and TCF4/LEF binding-sites for activating (α)-promoter, while activated NF-κBp65 (bound to NF-κB-cis-element), activates (β)-promoter in cancer-cells. DCLK1-S expression was examined in a cohort of 92 CRC patients; high-expressors had significantly worse overall-survival compared to low-expressors. Our novel findings' regarding usage of alternate (β)-promoter by hCRCs, suggests that DCLK1-S may represent an important target for preventing/inhibiting colon-cancers, and for eliminating colon-CSCs.