Targeting Redundant ROBO1 and SDF-1 Pathways Prevents Adult Hemangioblast Derived-EPC and CEC Activity Effectively Blocking Tumor Neovascularization.

Neovascularization is a key therapeutic target for cancer treatment. However, anti-angiogenic therapies have shown modest success, as tumors develop rapid resistance to treatment owing to activation of redundant pathways that aid vascularization. We hypothesized that simultaneously targeting different pathways of neovascularization will circumvent the current issue of drug resistance and offer enhanced therapeutic benefits. To test this hypothesis, we made use of two distinct models of tumor-neovascularization, which exhibit equally dense microvasculature but show disparate sensitivity to anti-SDF-1 treatment. Lewis lung carcinoma (LLC) is primarily a vasculogenic-tumor that is associated with HSC functioning as a hemangioblast to generate circulating Endothelial Progenitor Cells contributing to formation of new blood vessels, and responds to anti-SDF-1 treatment. B16F0 melanoma is an angiogenic-tumor that derives new blood vessels from existing vasculature and is resistant to anti-SDF-1 therapy. In this study, we observed increased expression of the angiogenic-factor, Robo1 predominantly expressed on the blood vessels of B16F0 tumor. Blockade of Robo1 by the decoy receptor, RoboN, resulted in reduced microvascular-density and tumor-growth. However, this was associated with mobilization of BM-cells into the B16F0 tumor, thus switching the mode of neovascularization from angiogenic to vasculogenic. The use of a combinatorial treatment of RoboN and the monoclonal anti-SDF-1 antibody effectively attenuated tumor-growth and inhibited both angiogenic and BM-derived microvessels.

Surgical blood ordering schedule for better inventory management: An experience from a tertiary care transfusion center.

Background: Overordering of blood has been a challenge faced by the blood bank staff. The present study addresses the role of maximum surgical blood ordering schedule (MSBOS) in optimizing the blood inventory management. Methods: The blood requests for elective surgical procedures from various surgical departments were reviewed to constitute MSBOS. Transfusion profile was assessed using crossmatch to transfused units (C/T) ratio, transfusion probability (TP), and transfusion index (TI). A cutoff of 0.3 and 5% value of TI and TP, respectively, was considered to decide on the type of crossmatch. The efficacy of MSBOS implementation has been determined prospectively by unpaired t test using SPSS software, version 20 (IBM, USA). Results: A total of 2674 patients were studied. Overall red cell usage rate was 15%. The comprehensive C/T ratio was 4.57. The C/T ratios for the various departments ranged from 1 to 8.5 (adjusted C/T ratio). Highest C/T ratio was observed for surgical procedures performed in the specialties of otorhinolaryngology and urology. A C/T ratio greater than 5 was noted in 30.4% of different types of surgical procedures. Of the 176 different types of elective surgical procedures studied, type and screen protocol was applicable for 75.5% (133) of the procedures. After implementation of MSBOS, the number of crossmatches reduced by 2152 and total working time saved in our laboratory is close to 75,320 man hours. Conclusion: MSBOS helps in identifying the common surgical procedures with low TP and is one of the efficient tools in preventing the overordering of the blood.

Epithelial-Mesenchymal Transition Suppresses AMPK and Sensitizes Cancer Cells to Pyroptosis under Energy Stress.

Epithelial-mesenchymal transition (EMT) is implicated in tumor metastasis and therapeutic resistance. It remains a challenge to target cancer cells that have undergone EMT. The Snail family of key EMT-inducing transcription factors directly binds to and transcriptionally represses not only epithelial genes but also a myriad of additional genomic targets that may carry out significant biological functions. Therefore, we reasoned that EMT inherently causes various concomitant phenotypes, some of which may create targetable vulnerabilities for cancer treatment. In the present study, we found that Snail transcription factors bind to the promoters of multiple genes encoding subunits of the AMP-activated protein kinase (AMPK) complex, and expression of AMPK genes was markedly downregulated by EMT. Accordingly, high AMPK expression in tumors correlated with epithelial cell markers and low AMPK expression in tumors was strongly associated with adverse prognosis. AMPK is the principal sensor of cellular energy status. In response to energy stress, AMPK is activated and critically reprograms cellular metabolism to restore energy homeostasis and maintain cell survival. We showed that activation of AMPK by energy stress was severely impaired by EMT. Consequently, EMT cancer cells became hypersensitive to a variety of energy stress conditions and primarily underwent pyroptosis, a regulated form of necrotic cell death. Collectively, the study suggests that EMT impedes the activation of AMPK signaling induced by energy stress and sensitizes cancer cells to pyroptotic cell death under energy stress conditions. Therefore, while EMT promotes malignant progression, it concurrently induces collateral vulnerabilities that may be therapeutically exploited.

Wnt pathway modulators in cancer therapeutics: An update on completed and ongoing clinical trials.

Wnt signaling plays an essential role in the initiation and progression of various types of cancer. Besides, the Wnt pathway components have been established as reliable biomarkers and potential targets for cancer therapy. Wnt signaling is categorized into canonical and noncanonical pathways. The canonical pathway is involved in cell survival, proliferation, differentiation and migration, while the noncanonical pathway regulates cell polarity and migration. Apart from its biological role in development and homeostasis, the Wnt pathway has been implicated in several pathological disorders, including cancer. As a result, inhibiting this pathway has been a focus of cancer research with multiple targetable candidates in development. In this review, our focus will be to summarize information about ongoing and completed clinical trials targeting various Wnt pathway components, along with describing current and emerging Wnt targeted therapies. In addition, we will discuss potential opportunities and associated challenges of inhibiting Wnt signaling for cancer therapy.

Comparison of perioperative patient comfort with 'enhanced recovery after surgery (ERAS) approach' versus 'traditional approach' for elective laparoscopic cholecystectomy.

BACKGROUND: Perioperative anxiety, hunger, thirst, fatigue, pain along with nausea and vomiting can influence a patient's recovery after surgery. We aimed to compare 'enhanced recovery after surgery' (ERAS) protocol with a traditional perioperative approach to evaluate a patient's recovery after elective laparoscopic cholecystectomy. METHODS: A prospective randomised controlled study was conducted after institutional ethical clearance on 50 patients undergoing elective laparoscopic cholecystectomy, and divided equally into two groups. In group 1 (traditional); standard fasting guidelines and routine perioperative management was implemented. In group 2 (ERAS); patients received appropriate multimedia information about surgery and anaesthesia besidecarbohydrate loading with tender coconut water on the previous night and on the morning of surgery. Standard guidelines of fasting for solids were followed. Intraoperatively, goal-directed fluid therapy and an inspired oxygen concentration of 60% were administered. Postoperatively, early diet and mobilisation were initiated. The primary outcome was the assessment of perioperative anxiety. Hunger, thirst, fatigue, pain, nausea, vomiting and overall perioperative experience were also evaluated. RESULTS: ERAS group had reduced anxiety prior to surgery: median (interquartile range) 3 (3-4) vs 2 (2-3) (P = 0.003), and at 6 h postoperatively: 4 (3-6) vs 3 (1-4) (P = 0.001). Hunger, thirst and fatigue (P < 0.01) were also decreased with better overall perioperative experience (5 [4-5] vs 6 [5-7], P = 0.004). Pain, nausea, vomiting and blood glucose were similar between the groups. CONCLUSION: 'ERAS approach reduces anxiety in addition to hunger, thirst and fatigue with enhanced overall perioperative comfort in patients undergoing laparoscopic cholecystectomy.

Suppression of lung cancer progression by isoliquiritigenin through its metabolite 2, 4, 2', 4'-Tetrahydroxychalcone.

BACKGROUND: Licorice is an herb extensively used for both culinary and medicinal purposes. Various constituents of licorice have been shown to exhibit anti-tumorigenic effect in diverse cancer types. However, majority of these studies focus on the aspect of their growth-suppressive role. In this study, we systematically analyzed known licorice's constituents on the goal of identifying component(s) that can effectively suppress both cell migration and growth. METHODS: Effect of licorice's constituents on cell growth was evaluated by MTT assay while cell migration was assessed by both wound-healing and Transwell assays. Cytoskeleton reorganization and focal adhesion assembly were visualized by immunofluorescence staining with labeled phalloidin and anti-paxillin antibody. Activity of Src in cells was judged by western blot using phosphor-Src416 antibody while Src kinase activity was measured using Promega Src kinase assay system. Anti-tumorigenic capabilities of isoliquiritigenin (ISL) and 2, 4, 2', 4'-Tetrahydroxychalcone (THC) were investigated using lung cancer xenograft model. RESULTS: Using a panel of lung cancer cell lines, ISL was identified as the only licorice's constituent capable of inhibiting both cell migration and growth. ISL-led inhibition in cell migration resulted from impaired cytoskeleton reorganization and focal adhesion assembly. Assessing the phosphorylation of 141 cytoskeleton dynamics-associated proteins revealed that ISL reduced the abundance of Tyr421-phosphorylation of cortactin, Tyr925- and Tyr861-phosphorylation of FAK, indicating the involvement of Src because these sites are known to be phosphorylated by Src. Enigmatically, ISL inhibited Src in cells while displayed no effect on Src activity in cell-free system. The discrepancy was explained by the observation that THC, one of the major ISL metabolite identified in lung cancer cells abrogated Src activity both in cells and cell-free system. Similar to ISL, THC deterred cell migration and abolished cytoskeleton reorganization/focal adhesion assembly. Furthermore, we showed both ISL and THC suppressed in vitro lung cancer cell invasion and in vivo tumor progression. CONCLUSION: Our study suggests that ISL inhibits lung cancer cell migration and tumorigenesis by interfering with Src through its metabolite THC. As licorice is safely used for culinary purposes, our study suggests that ISL or THC may be safely used as a Src inhibitor.

Formulation and evaluation of mixed polymeric micelles of quercetin for treatment of breast, ovarian, and multidrug resistant cancers.

BACKGROUND: Quercetin (QCT), a naturally occurring flavonoid has a wide array of pharmacological properties such as anticancer, antioxidant and anti-inflammatory activities. QCT has low solubility in water and poor bioavailability, which limited its use as a therapeutic molecule. Polymeric micelles (PMs) is a novel drug delivery system having characteristics like smaller particle size, higher drug loading, sustained drug release, high stability, increased cellular uptake and improved therapeutic potential. In the present study, we have formulated and characterized mixed PMs (MPMs) containing QCT for increasing its anticancer potential. METHODS: The MPMs were prepared by thin film hydration method, and their physicochemical properties were characterized. The in vitro anticancer activity of the MPMs were tested in breast (MCF-7 and MDA-MB-231, epithelial and metastatic cancer cell lines, respectively), and ovarian (SKOV-3 and NCI/ADR, epithelial and multi-drug resistant cell lines, respectively) cancer. RESULTS: The optimal MPM formulations were obtained from Pluronic polymers, P123 and P407 with molar ratio of 7:3 (A16); and P123, P407 and TPGS in the molar ratio of 7:2:1 (A22). The size of the particles before lyophilization (24.83±0.44 nm) and after lyophilisation (37.10±4.23 nm), drug loading (8.75±0.41%), and encapsulation efficiency (87.48±4.15%) for formulation A16 were determined. For formulation A22, the particle size before lyophilization, after lyophilization, drug loading and encapsulation efficiency were 26.37±2.19 nm, 45.88±13.80 nm, 9.01±0.11% and 90.07±1.09%, respectively. The MPMs exhibited sustained release of QCT compared to free QCT as demonstrated from in vitro release experiments. The solubility of QCT was markedly improved compared to pure QCT. The MPMs were highly stable in aqueous media as demonstrated by their low critical micelle concentration. The concentration which inhibited 50% growth (IC50) values of both micellar preparations in all the cancer cell lines were significantly less compared to free QCT. CONCLUSION: Both the MPMs containing QCT could be used for effective delivery to different type of cancer and may be considered for further development.

Inhibition of PI3K/Akt/mTOR signaling in PI3KR2-overexpressing colon cancer stem cells reduces tumor growth due to apoptosis.

In sporadic colon cancer, colon cancer stem cells (CCSCs) initiate tumorigenesis and may contribute to late disease recurrences and metastases. We previously showed that aldehyde dehydrogenase (ALDH) activity (as indicated by the ALDEFLUOR® assay) is an effective marker for highly enriching CCSCs for further evaluation. Here, we used comparative transcriptome and proteome approaches to identify signaling pathways overrepresented in the CCSC population. We found overexpression of several components of the phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathway, including PI3KR2, a regulatory subunit of PI3K. LY294002, a PI3K inhibitor, defined the contribution of the PI3K/Akt/mTOR signaling pathway in CCSCs. LY294002-treated CCSCs showed decreases in proliferation, sphere formation and self-renewal, in phosphorylation-dependent activation of Akt, and in expression of cyclin D1. Inhibition of PI3K in vivo reduced tumorigenicity, increased detection of cleaved caspase 3, an indicator of apoptosis, and elevated expression of the inflammatory chemokine, CXCL8. Collectively, these results indicate that PI3K/Akt/mTOR signaling controls CCSC proliferation and CCSC survival, and suggests that it would be useful to develop therapeutic agents that target this signaling pathway.

Epithelial-to-Pericyte Transition in Cancer.

During epithelial-to-mesenchymal transition (EMT), cells lose epithelial characteristics and acquire mesenchymal properties. These two processes are genetically separable and governed by distinct transcriptional programs, rendering the EMT outputs highly heterogeneous. Our recent study shows that the mesenchymal products generated by EMT often express multiple pericyte markers, associate with and stabilize blood vessels to fuel tumor growth, thus phenotypically and functionally resembling pericytes. Therefore, some EMT events represent epithelial-to-pericyte transition (EPT). The serum response factor (SRF) plays key roles in both EMT and differentiation of pericytes, and may inherently confer the pericyte attributes on EMT cancer cells. By impacting their intratumoral location and cell surface receptor expression, EPT may enable cancer cells to receive and respond to angiocrine factors produced by the vascular niche, and develop therapy resistance.

Relevance of epithelial-to-pericyte transition in cancer.

The relevance of epithelial-to-mesenchymal transition (EMT) in cancer is still under debate. Recently, we reported that EMT bestows key pericyte properties on cancer cells and may thus represent epithelial-to-pericyte transition (EPT). Carcinoma cells undergo EPT to stabilize blood vessels and fuel primary tumor growth. Association of EPT cancer cells with vascular niches may also promote resistance to therapy.

Epithelial-to-mesenchymal transition confers pericyte properties on cancer cells.

Carcinoma cells can acquire increased motility and invasiveness through epithelial-to-mesenchymal transition (EMT). However, the significance of EMT in cancer metastasis has been controversial, and the exact fates and functions of EMT cancer cells in vivo remain inadequately understood. Here, we tracked epithelial cancer cells that underwent inducible or spontaneous EMT in various tumor transplantation models. Unlike epithelial cells, the majority of EMT cancer cells were specifically located in the perivascular space and closely associated with blood vessels. EMT markedly activated multiple pericyte markers in carcinoma cells, in particular PDGFR-ß and N-cadherin, which enabled EMT cells to be chemoattracted towards and physically interact with endothelium. In tumor xenografts generated from carcinoma cells that were prone to spontaneous EMT, a substantial fraction of the pericytes associated with tumor vasculature were derived from EMT cancer cells. Depletion of such EMT cells in transplanted tumors diminished pericyte coverage, impaired vascular integrity, and attenuated tumor growth. These findings suggest that EMT confers key pericyte attributes on cancer cells. The resulting EMT cells phenotypically and functionally resemble pericytes and are indispensable for vascular stabilization and sustained tumor growth. This study thus proposes a previously unrecognized role for EMT in cancer.

MOF Acetylates the Histone Demethylase LSD1 to Suppress Epithelial-to-Mesenchymal Transition.

The histone demethylase LSD1 facilitates epithelial-to-mesenchymal transition (EMT) and tumor progression by repressing epithelial marker expression. However, little is known about how its function may be modulated. Here, we report that LSD1 is acetylated in epithelial but not mesenchymal cells. Acetylation of LSD1 reduces its association with nucleosomes, thus increasing histone H3K4 methylation at its target genes and activating transcription. The MOF acetyltransferase interacts with LSD1 and is responsible for its acetylation. MOF is preferentially expressed in epithelial cells and is downregulated by EMT-inducing signals. Expression of exogenous MOF impedes LSD1 binding to epithelial gene promoters and histone demethylation, thereby suppressing EMT and tumor invasion. Conversely, MOF depletion enhances EMT and tumor metastasis. In human cancer, high MOF expression correlates with epithelial markers and a favorable prognosis. These findings provide insight into the regulation of LSD1 and EMT and identify MOF as a critical suppressor of EMT and tumor progression.

Src drives the Warburg effect and therapy resistance by inactivating pyruvate dehydrogenase through tyrosine-289 phosphorylation.

The Warburg effect, which reflects cancer cells' preference for aerobic glycolysis over glucose oxidation, contributes to tumor growth, progression and therapy resistance. The restraint on pyruvate flux into mitochondrial oxidative metabolism in cancer cells is in part attributed to the inhibition of pyruvate dehydrogenase (PDH) complex. Src is a prominent oncogenic non-receptor tyrosine kinase that promotes cancer cell proliferation, invasion, metastasis and resistance to conventional and targeted therapies. However, the potential role of Src in tumor metabolism remained unclear. Here we report that activation of Src attenuated PDH activity and generation of reactive oxygen species (ROS). Conversely, Src inhibitors activated PDH and increased cellular ROS levels. Src inactivated PDH through direct phosphorylation of tyrosine-289 of PDH E1α subunit (PDHA1). Indeed, Src was the main kinase responsible for PDHA1 tyrosine phosphorylation in cancer cells. Expression of a tyrosine-289 non-phosphorable PDHA1 mutant in Src-hyperactivated cancer cells restored PDH activity, increased mitochondrial respiration and oxidative stress, decreased experimental metastasis, and sensitized cancer cells to pro-oxidant treatment. The results suggest that Src contributes to the Warburg phenotype by inactivating PDH through tyrosine phosphorylation, and the metabolic effect of Src is essential for Src-driven malignancy and therapy resistance. Combination therapies consisting of both Src inhibitors and pro-oxidants may improve anticancer efficacy.

Cancer cells remodel themselves and vasculature to overcome the endothelial barrier.

Metastasis refers to the spread of cancer cells from a primary tumor to distant organs mostly via the bloodstream. During the metastatic process, cancer cells invade blood vessels to enter circulation, and later exit the vasculature at a distant site. Endothelial cells that line blood vessels normally serve as a barrier to the movement of cells into or out of the blood. It is thus critical to understand how metastatic cancer cells overcome the endothelial barrier. Epithelial cancer cells acquire increased motility and invasiveness through epithelial-to-mesenchymal transition (EMT), which enables them to move toward vasculature. Cancer cells also express a variety of adhesion molecules that allow them to attach to vascular endothelium. Finally, cancer cells secrete or induce growth factors and cytokines to actively prompt vascular hyperpermeability that compromises endothelial barrier function and facilitates transmigration of cancer cells through the vascular wall. Elucidation of the mechanisms underlying metastatic dissemination may help develop new anti-metastasis therapeutics.

FBXO11 promotes ubiquitination of the Snail family of transcription factors in cancer progression and epidermal development.

The Snail family of transcription factors are core inducers of epithelial-to-mesenchymal transition (EMT). Here we show that the F-box protein FBXO11 recognizes and promotes ubiquitin-mediated degradation of multiple Snail family members including Scratch. The association between FBXO11 and Snai1 in vitro is independent of Snai1 phosphorylation. Overexpression of FBXO11 in mesenchymal cells reduces Snail protein abundance and cellular invasiveness. Conversely, depletion of endogenous FBXO11 in epithelial cancer cells causes Snail protein accumulation, EMT, and tumor invasion, as well as loss of estrogen receptor expression in breast cancer cells. Expression of FBXO11 is downregulated by EMT-inducing signals TGFß and nickel. In human cancer, high FBXO11 levels correlate with expression of epithelial markers and favorable prognosis. The results suggest that FBXO11 sustains the epithelial state and inhibits cancer progression. Inactivation of FBXO11 in mice leads to neonatal lethality, epidermal thickening, and increased Snail protein levels in epidermis, validating that FBXO11 is a physiological ubiquitin ligase of Snail. Moreover, in C. elegans, the FBXO11 mutant phenotype is attributed to the Snail factors as it is suppressed by inactivation/depletion of Snail homologs. Collectively, these findings suggest that the FBXO11-Snail regulatory axis is evolutionarily conserved and critically governs carcinoma progression and mammalian epidermal development.

The malignant brain tumor (MBT) domain protein SFMBT1 is an integral histone reader subunit of the LSD1 demethylase complex for chromatin association and epithelial-to-mesenchymal transition.

Chromatin readers decipher the functional readouts of histone modifications by recruiting specific effector complexes for subsequent epigenetic reprogramming. The LSD1 (also known as KDM1A) histone demethylase complex modifies chromatin and represses transcription in part by catalyzing demethylation of dimethylated histone H3 lysine 4 (H3K4me2), a mark for active transcription. However, none of its currently known subunits recognizes methylated histones. The Snai1 family transcription factors are central drivers of epithelial-to-mesenchymal transition (EMT) by which epithelial cells acquire enhanced invasiveness. Snai1-mediated transcriptional repression of epithelial genes depends on its recruitment of the LSD1 complex and ensuing demethylation of H3K4me2 at its target genes. Through biochemical purification, we identified the MBT domain-containing protein SFMBT1 as a novel component of the LSD1 complex associated with Snai1. Unlike other mammalian MBT domain proteins characterized to date that selectively recognize mono- and dimethylated lysines, SFMBT1 binds di- and trimethyl H3K4, both of which are enriched at active promoters. We show that SFMBT1 is essential for Snai1-dependent recruitment of LSD1 to chromatin, demethylation of H3K4me2, transcriptional repression of epithelial markers, and induction of EMT by TGFß. Carcinogenic metal nickel is a widespread environmental and occupational pollutant. Nickel alters gene expression and induces EMT. We demonstrate the nickel-initiated effects are dependent on LSD1-SFMBT1-mediated chromatin modification. Furthermore, in human cancer, expression of SFMBT1 is associated with mesenchymal markers and unfavorable prognosis. These results highlight a critical role of SFMBT1 in epigenetic regulation, EMT, and cancer.

Symmetrical peripheral gangrene-a case report and brief review.

A 30 year-old gentleman presented to casualty with history of pain abdomen for six days, fever and decreased urine output since two days. He was in a state of septic shock and was diagnosed to have intestinal perforation. His peripheral pulses were not palpable except for the femoral and brachial vessels. Despite fluid resuscitation, he needed infusion of high doses of dopamine and noradrenaline to maintain his blood pressure. He was operated for repair of perforation. On the first postoperative day, in the intensive care unit, vasopressin infusion was added in view of persistent hypotension. Appropriate fluid resuscitation and antibiotic therapy helped to wean him off inotropes and vasopressors by the second postoperative day. On the 3rd postoperative day, however, the patient developed discolouration and blebs on the fingers of left hand, followed by the right hand and then both the lower limbs. Subsequently, over a period of 10 days, this progressed to gangrene formation in the hands despite the patient being haemodynamically stable without any inotropes or vasopressors in this period. We conclude that the septic shock is a systemic derangement affecting all organ systems including coagulation and microcirculation. Early recognition and prompt management of sepsis, optimisation of fluid status to wean off the inotropes and vasopressors at the earliest is necessary to avoid catastrophes such as symmetrical peripheral gangrene.

Transition from colitis to cancer: high Wnt activity sustains the tumor-initiating potential of colon cancer stem cell precursors.

Ulcerative colitis (UC) increases the risk of colorectal cancer (CRC), but the mechanisms involved in colitis-to-cancer transition (CCT) are not well understood. CCT may involve a inflammation-dysplasia-carcinoma progression sequence compared with the better characterized adenoma-carcinoma progression sequence associated with sporadic CRC. One common thread may be activating mutations in components of the Wnt/ß-catenin signaling pathway, which occur commonly as early events in sporadic CRC. To examine this hypothesis, we evaluated possible associations between Wnt/ß-catenin signaling and CCT based on the cancer stem cell (CSC) model. Wnt/ß-catenin immunostaining indicated that UC patients have a level of Wnt-pathway-active cells that is intermediate between normal colon and CRC. These UC cells exhibiting activation of the Wnt pathway constituted a major subpopulation (52% + 7.21) of the colonic epithelial cells positive for aldehyde dehydrogenase (ALDH), a putative marker of precursor colon CSC (pCCSC). We further fractionated this subpopulation of pCCSC using a Wnt pathway reporter assay. Over successive passages, pCCSCs with the highest Wnt activity exhibited higher clonogenic and tumorigenic potential than pCCSCs with the lowest Wnt activity, thereby establishing the key role of Wnt activity in driving CSC-like properties in these cells. Notably, 5/20 single cell injections of high-Wnt pCCSC resulted in tumor formation, suggesting a correlation with CCT. Attenuation of Wnt/ß-catenin in high-Wnt pCCSC by shRNA-mediated downregulation or pharmacological inhibition significantly reduced tumor growth rates. Overall, the results of our study indicates (i) that early activation of Wnt/ß-catenin signaling is critical for CCT and (ii) that high levels of Wnt/ß-catenin signaling can further demarcate high-ALDH tumor-initiating cells in the nondysplastic epithelium of UC patients. As such, our findings offer plausible diagnostic markers and therapeutic target in the Wnt signaling pathway for early intervention in CCT.

ALDH as a marker for enriching tumorigenic human colonic stem cells.

Aldehyde dehydrogenase (ALDH) can be used as a marker to isolate, propagate, and track normal and cancerous human colon stem cells. To determine their tumorigenic potential, tissues obtained from proximal (normal counterpart) and distal (cancerous) colon of colon cancer patients are implanted into NOD-SCID mice. In parallel, ALDH(high) and ALDH(low) cells are isolated via Florescence Associated Cell Sorting (FACS) after the dissociation of distal and proximal colon tissues into a single-cell suspension. Flow cytometry for ALDH(high) and ALDH(low) cells is possible with the ALDEFLUOR assay. Following cell sorting, ALDH-enriched cells are tested for their tumorigenic potential in vivo as xenografts. Owing to cancer stem cell properties, ALDH(high) cells could be propagated in vivo by serial passaging of the human tissue as xenografts and in vitro as suspension cultures called sphere cultures. In this unit, all the above-mentioned methods to isolate and propagate colon cancer stem cells using ALDH as a stem cell marker are described in detail.