Novel serum markers HSP60, CHI3L1, and IGFBP-2 in metastatic colorectal cancer

A proteomic classifier panel for early screening of colorectal cancer: a case control study

BACKGROUND

Diagnosis of colorectal cancer (CRC) during early stages can greatly improve patient outcome. Although technical advances in the field of genomics and proteomics have identified a number of candidate biomarkers for non-invasive screening and diagnosis, developing more sensitive and specific methods with improved cost-effectiveness and patient compliance has tremendous potential to help combat the disease.

METHODS

We enrolled three cohorts of 479 subjects, including 226 CRC cases, 197 healthy controls, and 56 advanced precancerous lesions (APC). In the discovery cohort, we used quantitative mass spectrometry to measure the expression profile of plasma proteins and applied machine-learning to select candidate proteins. We then developed a targeted mass spectrometry assay to measure plasma concentrations of seven proteins and a logistic regression classifier to distinguish CRC from healthy subjects. The classifier was further validated using two independent cohorts.

RESULTS

The seven-protein panel consisted of leucine rich alpha-2-glycoprotein 1 (LRG1), complement C9 (C9), insulin-like growth factor binding protein 2 (IGFBP2), carnosine dipeptidase 1 (CNDP1), inter-alpha-trypsin inhibitor heavy chain 3 (ITIH3), serpin family A member 1 (SERPINA1), and alpha-1-acid glycoprotein 1 (ORM1). The panel classified CRC and healthy subjects with high accuracy, since the area under curve (AUC) of the training and testing cohort reached 0.954 and 0.958. The AUC of the two independent validation cohorts was 0.905 and 0.909. In one validation cohort, the panel had an overall sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 89.9%, 81.8%, 89.2%, and 82.9%, respectively. In another blinded validation cohort, the panel classified CRC from healthy subjects with a sensitivity of 81.5%, specificity of 97.9%, and overall accuracy of 92.0%. Finally, the panel was able to detect APC with a sensitivity of 49%.

CONCLUSIONS

This seven-protein classifier is a clear improvement compared to previously published blood-based protein biomarkers for detecting early-stage CRC, and is of translational potential to develop into a clinically useful assay.

Knockdown of heat shock protein family D member 1 (HSPD1) promotes proliferation and migration of ovarian cancer cells via disrupting the stability of mitochondrial 3-oxoacyl-ACP synthase (OXSM)

BACKGROUND

Heat shock protein 60 (HSP60) is essential for the folding and assembly of newly imported proteins to the mitochondria. HSP60 is overexpressed in most types of cancer, but its association with ovarian cancer is still in dispute. SKOV3 and OVCAR3 were used as experimental models after comparing the expression level of mitochondrial HSP60 in a normal human ovarian epithelial cell line and four ovarian cancer cell lines.

RESULTS

Low HSPD1 (Heat Shock Protein Family D (HSP60) Member 1) expression was associated with unfavorable prognosis in ovarian cancer patients. Knockdown of HSPD1 significantly promoted the proliferation and migration of ovarian cancer cells. The differentially expressed proteins after HSPD1 knockdown were enriched in the lipoic acid (LA) biosynthesis and metabolism pathway, in which mitochondrial 3-oxoacyl-ACP synthase (OXSM) was the most downregulated protein and responsible for lipoic acid synthesis. HSP60 interacted with OXSM and overexpression of OXSM or LA treatment could reverse proliferation promotion mediated by HSPD1 knockdown.

CONCLUSIONS

HSP60 interacted with OXSM and maintained its stability. Knockdown of HSPD1 could promote the proliferation and migration of SKOV3 and OVCAR3 via lowering the protein level of OXSM and LA synthesis.

A study on expression level and nutritional status of IGFBP-2 after left neck anastomosis combined with placement of feeding nutritional applicators carrying ^(125)I particles in the treatment of esophageal cancer

Background

To explore the changes and significance of the expression level and nutritional status of human insulin-like growth factor binding protein-2 (IGFBP2) after the treatment of esophageal cancer with left neck anastomosis combined with placement of feeding nutritional applicators carrying ^(125)I particles.

Methods

A total of 110 patients with esophageal cancer (observation group: left neck anastomosis combined with placement of feeding nutritional applicators carrying ^(125)I particles) and 100 healthy people (control group) were enrolled at the same period. Then enzyme-linked immunosorbent assay (ELISA) was carried out to detect level of IGFBP-2. Lymphocyte count and serum albumin were measured by immune analyzer and automatic protein analyzer to evaluate nutritional status. Logistic regression analysis was used to analyze the relationship between serum IGFBP-2, nutritional status and prognosis of esophageal cancer after combined treatment.

Results

The albumin, lymphocyte absolute value and PNI detection value of the control group were lower than those of the observation group 1 month after treatment, and the difference was statistically significant compared with the control group. The detection value of IGFBP-2 in early patients before and after treatment was lower than that in middle and late patients, and the detection values of albumin, lymphocyte absolute value and PNI were higher than those in middle and late patients, the differences were statistically significant. Serum IGFBP-2 level was negatively correlated with PNI, and albumin and lymphocyte absolute value were positively correlated with PNI. The detection value of IGFBP-2 in patients with good prognosis was significantly lower than that in patients with poor prognosis, and the detection values of albumin, lymphocyte absolute value and PNI were significantly higher than those in patients with poor prognosis. The AUC (0.887,95% CI: 0.799-0.975) of IGFBP-2, albumin, lymphocyte absolute value and PNI in predicting poor prognosis of esophageal cancer was the largest, and the sensitivity and specificity were 94.12% and 92.47%, respectively.

Conclusions

Left neck anastomosis combined with ^(125)I particle application nutritional tube is helpful for the decrease of serum IGFBP-2 and the increase of various nutritional status indicators, which is beneficial for the improvement of the patient's condition.

EPLIN, a Putative Tumour Suppressor in Colorectal Cancer, Implications in Drug Resistance

Colorectal cancer is a serious threat to human health. Poor prognosis and frequently reported drug resistance urges research into novel biomarkers and mechanisms to aid in the understanding of the development and progression of colorectal cancer and to optimise therapeutic strategies. In the current study, we investigated the roles of a putative tumour suppressor, EPLIN, in colorectal cancer. Our clinical colorectal cancer cohort and online databases revealed a downregulation of EPLIN in colorectal cancer tissues compared with normal tissues. The reduced expression of EPLIN was associated with poor clinical outcomes of patients. In vitro cellular function assays showed that EPLIN elicited an inhibitory effect on cellular growth, adhesion, migration and invasion. Utilising a protein microarray on protein samples from normal and tumour patient tissues suggested HSP60, Her2 and other signalling events were novel potential interacting partners of EPLIN. It was further revealed that EPLIN and HSP60 were negative regulators of Her2 in colorectal cancer cells. The clinical cohort also demonstrated that expression of HSP60 and Her2 affected clinical outcomes, but most interestingly the combination of EPLIN, HSP60 and Her2 was able to identify patients with the most unfavourable clinical outcome by independently predicting patient overall survival and disease free survival. Furthermore, EPLIN and HSP60 exhibited potential to regulate cellular response to chemotherapeutic and EGFR/Her2 targeted therapeutic agents. In conclusion, EPLIN is an important prognostic factor for patients with colon cancer and reduced EPLIN in CRC contributes to aggressive traits of CRC cells and their responses to chemotherapeutic drugs. Collectively, EPLIN is a pivotal factor for the development and progression of colorectal cancer and has important clinical and therapeutic values in this cancer type.

The Insulin-like Growth Factor System and Colorectal Cancer

Insulin-like growth factors (IGFs) are peptides which exert mitogenic, endocrine and cytokine activities. Together with their receptors, binding proteins and associated molecules, they participate in numerous pathophysiological processes, including cancer development. Colorectal cancer (CRC) is a disease with high incidence and mortality rates worldwide, whose etiology usually represents a combination of the environmental and genetic factors. IGFs are most often increased in CRC, enabling excessive autocrine/paracrine stimulation of the cell growth. Overexpression or increased activation/accessibility of IGF receptors is a coinciding step which transmits IGF-related signals. A number of molecules and biochemical mechanisms exert modulatory effects shaping the final outcome of the IGF-stimulated processes, frequently leading to neoplastic transformation in the case of irreparable disbalance. The IGF system and related molecules and pathways which participate in the development of CRC are the focus of this review.

The mitochondrial unfolded protein response (UPRmt): shielding against toxicity to mitochondria in cancer

Mitochondria are essential for tumor growth and progression. However, the heavy demand for mitochondrial activity in cancer leads to increased production of mitochondrial reactive oxygen species (mtROS), accumulation of mutations in mitochondrial DNA, and development of mitochondrial dysfunction. If left unchecked, excessive mtROS can damage and unfold proteins in the mitochondria to an extent that becomes lethal to the tumor. Cellular systems have evolved to combat mtROS and alleviate mitochondrial stress through a quality control mechanism called the mitochondrial unfolded protein response (UPR^mt). The UPR^mt system is composed of chaperones and proteases, which promote protein folding or eliminate mitochondrial proteins damaged by mtROS, respectively. UPR^mt is conserved and activated in cancer in response to mitochondrial stress to maintain mitochondrial integrity and support tumor growth. In this review, we discuss how mitochondria become dysfunctional in cancer and highlight the tumor-promoting functions of key components of the UPR^mt.

Heat Shock Proteins and HSF1 in Cancer

Fitness of cells is dependent on protein homeostasis which is maintained by cooperative activities of protein chaperones and proteolytic machinery. Upon encountering protein-damaging conditions, cells activate the heat-shock response (HSR) which involves HSF1-mediated transcriptional upregulation of a group of chaperones - the heat shock proteins (HSPs). Cancer cells experience high levels of proteotoxic stress due to the production of mutated proteins, aneuploidy-induced excess of components of multiprotein complexes, increased translation rates, and dysregulated metabolism. To cope with this chronic state of proteotoxic stress, cancers almost invariably upregulate major components of HSR, including HSF1 and individual HSPs. Some oncogenic programs show dependence or coupling with a particular HSR factor (such as frequent coamplification of HSF1 and MYC genes). Elevated levels of HSPs and HSF1 are typically associated with drug resistance and poor clinical outcomes in various malignancies. The non-oncogene dependence ("addiction") on protein quality controls represents a pancancer target in treating human malignancies, offering a potential to enhance efficacy of standard and targeted chemotherapy and immune checkpoint inhibitors. In cancers with specific dependencies, HSR components can serve as alternative targets to poorly druggable oncogenic drivers.

Diabetes and Colorectal Cancer Risk: A New Look at Molecular Mechanisms and Potential Role of Novel Antidiabetic Agents

Epidemiological data have demonstrated a significant association between the presence of type 2 diabetes mellitus (T2DM) and the development of colorectal cancer (CRC). Chronic hyperglycemia, insulin resistance, oxidative stress, and inflammation, the processes inherent to T2DM, also play active roles in the onset and progression of CRC. Recently, small dense low-density lipoprotein (LDL) particles, a typical characteristic of diabetic dyslipidemia, emerged as another possible underlying link between T2DM and CRC. Growing evidence suggests that antidiabetic medications may have beneficial effects in CRC prevention. According to findings from a limited number of preclinical and clinical studies, glucagon-like peptide-1 receptor agonists (GLP-1RAs) could be a promising strategy in reducing the incidence of CRC in patients with diabetes. However, available findings are inconclusive, and further studies are required. In this review, novel evidence on molecular mechanisms linking T2DM with CRC development, progression, and survival will be discussed. In addition, the potential role of GLP-1RAs therapies in CRC prevention will also be evaluated.

Liquid Biopsy-Based Colorectal Cancer Screening via Surface Markers of Circulating Tumor Cells

Colorectal cancer (CRC) is ranked second for cancer-related deaths worldwide with approximately half of the patients being diagnosed at the late stages. The untimely detection of CRC results in advancement to the metastatic stage and nearly 90% of cancer-related deaths. The early detection of CRC is crucial to decrease its overall incidence and mortality rates. The recent introduction of circulating tumor cells (CTCs) has enabled a less invasive sampling method from liquid biopsies, besides revealing key information toward CRC metastasis. The current gold standard for CTC identification is the CellSearch® system (Veridex). This first-generation instrumentation relies on a single cell surface marker (CSM) to capture and count CTCs. Detection of CTCs allows the identification of patients at risk for metastasis, whereas CTC enumeration could improve risk assessment, monitoring of systemic therapy, and detection of therapy resistance in advanced metastatic CRC. In this review, we compared the pros and cons between single CSM-based CTC enrichment techniques and multi-marker-based systems. We also highlighted the challenges faced in the routine implementation of CSM-dependent CTC detection methods in CRC screening, prediction, prognosis, disease monitoring, and therapy selection toward precision medicine, as well as the dwelling on post-CTC analysis and characterization methods.

Ins and Outs of Heat Shock Proteins in Colorectal Carcinoma: Its Role in Carcinogenesis and Therapeutic Perspectives

Cancer cells can reprogram their metabolic activities and undergo uncontrolled proliferation by utilizing the power of heat shock proteins (HSPs). HSPs are highly conserved chaperones that facilitate the folding of intracellular proteins under stress. Constitutively, HSPs are expressed at low levels, but their expression upregulates in response to a wide variety of insults, including anticancer drugs, allowing cancer cells to develop chemoresistance. In recent years, several researchers have reported that HSPs could be an important therapeutic target in difficult-to-treat cancers such as colorectal carcinoma (CRC). Worldwide, CRC is the second most common type of cancer and the second leading cause of cancer-related deaths. The molecular complexity of CRC and the coexisting inflammatory conditions present a significant obstacle to developing effective treatment. Recently, considerable progress has been made in enhancing our understanding of the role of HSPs in CRC pathogenesis. Moreover, novel therapeutic strategies targeting HSPs, either alone or in combination with other anticancer agents, have been reported. Herein, we present an overview of the functional mechanisms and the diagnostic and prognostic potential of HSPs in CRC. We also discuss emerging anti-CRC strategies based on targeting HSPs.

WEE1 inhibition reverses trastuzumab resistance in HER2-positive cancers

BACKGROUND

To date, many efforts have been made to understand the resistance mechanism of trastuzumab in human epidermal growth factor receptor 2 (HER2)-positive breast and gastric cancer. However, there is still a huge unmet medical need for patients with trastuzumab resistance.

METHODS

In our study, we generated four trastuzumab-resistant (HR) cancer cell lines from ERBB2-amplified gastric and biliary tract cancer cell lines (SNU-216, NCI-N87, SNU-2670, and SNU-2773).

RESULTS

Here, we found higher PD-L1 expression in trastuzumab-resistant (HR) HER2-positive cancer cells than in parental cells, and blocking PD-L1 reversed the resistance to trastuzumab in HR cells. Trastuzumab upregulated PD-L1 expression via NF-κB activation in both parental and HR cells, however, led to DNA damage only in parental cells. The WEE1 inhibitor adavosertib, which downregulates PD-L1 expression, enhanced trastuzumab efficacy by blocking BRCA1-CMTM6-PD-L1 signals and the HER2-CDCP-1-SRC axis. Additionally, the levels of galectin-9, CD163, FoxP3, and CTLA-4 were diminished by blocking WEE1 in the presence of human PBMCs in vitro.

CONCLUSION

Taken together, the strategy of co-targeting HER2 and WEE1 could overcome resistance to trastuzumab in HER2-positive cancers, supporting further clinical development in HER2-positive cancer patients.

HSP60-knockdown suppresses proliferation in colorectal cancer cells via activating the adenine/AMPK/mTOR signaling pathway

Colorectal cancer (CRC) is the fourth most lethal cancer in the world. Heat shock protein 60 (HSP60), a mitochondrial chaperone that maintains mitochondrial proteostasis, is highly expressed in tumors compared with in paracancerous tissues, suggesting that high HSP60 expression benefits tumor growth. To determine the effects of HSP60 expression on tumor progression, stable HSP60-knockdown HCT116 cells were constructed in the present study, revealing that knockdown of HSP60 inhibited cell proliferation. Proteomic analysis demonstrated that mitochondrial proteins were downregulated, indicating that knockdown of HSP60 disrupted mitochondrial homeostasis. Metabolomic analysis demonstrated that cellular adenine levels were >30-fold higher in HSP60-knockdown cells than in control cells. It was further confirmed that elevated adenine activated the AMPK signaling pathway, which inhibited mTOR-regulated protein synthesis to slow down cell proliferation. Overall, the current results provide a valuable resource for understanding mitochondrial function in CRC, suggesting that HSP60 may be a potential target for CRC intervention.

Emerging Roles for Browning of White Adipose Tissue in Prostate Cancer Malignant Behaviour

In addition to its well-known role as an energy repository, adipose tissue is one of the largest endocrine organs in the organism due to its ability to synthesize and release different bioactive molecules. Two main types of adipose tissue have been described, namely white adipose tissue (WAT) with a classical energy storage function, and brown adipose tissue (BAT) with thermogenic activity. The prostate, an exocrine gland present in the reproductive system of most mammals, is surrounded by periprostatic adipose tissue (PPAT) that contributes to maintaining glandular homeostasis in conjunction with other cell types of the microenvironment. In pathological conditions such as the development and progression of prostate cancer, adipose tissue plays a key role through paracrine and endocrine signaling. In this context, the role of WAT has been thoroughly studied. However, the influence of BAT on prostate tumor development and progression is unclear and has received much less attention. This review tries to bring an update on the role of different factors released by WAT which may participate in the initiation, progression and metastasis, as well as to compile the available information on BAT to discuss and open a new field of knowledge about the possible protective role of BAT in prostate cancer.

Deciphering molecular mechanisms of metastasis: novel insights into targets and therapeutics

BACKGROUND

The transition of a primary tumour to metastatic progression is driven by dynamic molecular changes, including genetic and epigenetic alterations. The metastatic cascade involves bidirectional interactions among extracellular and intracellular components leading to disintegration of cellular junctions, cytoskeleton reorganization and epithelial to mesenchymal transition. These events promote metastasis by reprogramming the primary cancer cell's molecular framework, enabling them to cause local invasion, anchorage-independent survival, cell death and immune resistance, extravasation and colonization of distant organs. Metastasis follows a site-specific pattern that is still poorly understood at the molecular level. Although various drugs have been tested clinically across different metastatic cancer types, it has remained difficult to develop efficacious therapeutics due to complex molecular layers involved in metastasis as well as experimental limitations.

CONCLUSIONS

In this review, a systemic evaluation of the molecular mechanisms of metastasis is outlined and the potential molecular components and their status as therapeutic targets and the associated pre-clinical and clinical agents available or under investigations are discussed. Integrative methods like pan-cancer data analysis, which can provide clinical insights into both targets and treatment decisions and help in the identification of crucial components driving metastasis such as mutational profiles, gene signatures, associated pathways, site specificities and disease-gene phenotypes, are discussed. A multi-level data integration of the metastasis signatures across multiple primary and metastatic cancer types may facilitate the development of precision medicine and open up new opportunities for future therapies.

Exploiting the HSP60/10 chaperonin system as a chemotherapeutic target for colorectal cancer

Over the past few decades, an increasing variety of molecular chaperones have been investigated for their role in tumorigenesis and as potential chemotherapeutic targets; however, the 60 kDa Heat Shock Protein (HSP60), along with its HSP10 co-chaperone, have received little attention in this regard. In the present study, we investigated two series of our previously developed inhibitors of the bacterial homolog of HSP60/10, called GroEL/ES, for their selective cytotoxicity to cancerous over non-cancerous colorectal cells. We further developed a third "hybrid" series of analogs to identify new candidates with superior properties than the two parent scaffolds. Using a series of well-established HSP60/10 biochemical screens and cell-viability assays, we identified 24 inhibitors (14%) that exhibited > 3-fold selectivity for targeting colorectal cancer over non-cancerous cells. Notably, cell viability EC₅₀ results correlated with the relative expression of HSP60 in the mitochondria, suggesting a potential for this HSP60-targeting chemotherapeutic strategy as emerging evidence indicates that HSP60 is up-regulated in colorectal cancer tumors. Further examination of five lead candidates indicated their ability to inhibit the clonogenicity and migration of colorectal cancer cells. These promising results are the most thorough analysis and first reported instance of HSP60/10 inhibitors being able to selectively target colorectal cancer cells and highlight the potential of the HSP60/10 chaperonin system as a viable chemotherapeutic target.

HSP60 participates in the anti-glioma effects of curcumin

The chaperone protein heat shock protein 60 (HSP60) is considered a tumor promoter in several types of primary human tumors, where it orchestrates a broad range of survival programs. Curcumin (CCM) is well-established to exhibit several anticancer properties with an excellent safety profile. Our previous study showed that CCM suppresses extracellular HSP60 expression, which is typically released by activated microglia, and acts as an inflammatory factor by binding to Toll-like receptor 4 (TLR-4) on the cell membrane. The present study assessed whether CCM exerted its anti-neuroglioma effects on U87 cells via inhibition of HSP60/TLR-4 signaling, similar to that in microglia. The results demonstrated that CCM significantly inhibited the viability and invasive capacity of neuroglioma U87 cells as evidenced by a Cell Counting Kit-8 assay. Western blotting and ELISA results showed that CCM decreased the expression of HSP60 and its transcriptional factor, heat shock factor 1, and reduced HSP60 release. Accordingly, TLR-4, as the target of HSP60, and its downstream signaling proteins myeloid differentiation primary response 88 (MYD88), NF-κB, inducible nitric oxide synthase and cytokines IL-1β and IL-6 were downregulated by CCM. The expression levels of apoptotic factors associated with NF-κB activation, including TNF-α and caspase-3 were increased in U87 cells by CCM treatment, while p53 expression, a tumor suppressor, was shown to be decreased. Based on the results of the present study, CCM may exert its anti-tumor effects in U87 cells by inhibiting the HSP60/TLR-4/MYD88/NF-κB pathway and inducing tumor cell apoptosis. Thus, CCM may be used as a potential therapy for the clinical treatment of neuroglioma.

The New Proactive Approach and Precision Medicine in Crohn's Disease

The proactive approach to Crohn's disease (CD) management advocates moving toward algorithmic tight-control scenarios that are designed for each CD phenotype to guide remission induction, maintenance therapy, active monitoring, and multidisciplinary care to manage the complexities of each inflammatory bowel disease (IBD) patient. This requires accurate initial clinical, laboratory, radiological, endoscopic, and/or tissue diagnosis for proper phenotypic stratification of each CD patient. A substantial proportion of patients in symptomatic remission have been reported to demonstrate evidence of active disease, with elevated fecal calprotectin(FC) and C-reactive protein (CRP) levels as a hallmark for mucosal inflammation. Active mucosal inflammation, and elevated CRP and fecal calprotectin (FC) have been shown to be good predictors of clinical relapse, disease progression, and complications in IBD patients. The next frontier of treatment is personalized medicine or precision medicine to help solve the problem of IBD heterogeneity and variable responses to treatment. Personalized medicine has the potential to increase the efficacy and/or reduce potential adverse effects of treatment for each CD phenotype. However, there is currently an unmet need for better elucidation of the inflammatory biopathways and genetic signatures of each IBD phenotype, so personalized medicine can specifically target the underlying cause of the disease and provide maximal efficacy to each patient.

L1CAM, CA9, KLK6, HPN, and ALDH1A1 as Potential Serum Markers in Primary and Metastatic Colorectal Cancer Screening

BACKGROUND

Colorectal cancer (CRC) screening at the earlier stages could effectively decrease CRC-related mortality and incidence; however, accurate screening strategies are still lacking. Considerable interest has been generated in the detection of less invasive tests requiring a small sample volume with the potential to detect several cancer biomarkers simultaneously. Due to this, the ELISA-based method was undertaken in this study.

METHODS

Concentrations of neural cell adhesion molecule L1 (L1CAM), carbonic anhydrase IX (CA9), mesothelin (MSLN), midkine (MDK), hepsin (HPN), kallikrein 6 (KLK6), transglutaminase 2 (TGM2) aldehyde dehydrogenase 1 family, member A1 (ALDH1A1), epithelial cell adhesion molecule (EpCAM), and cluster of differentiation 44 (CD44) from blood serum of 36 primary CRC and 24 metastatic CRC (mCRC) were calculated via MAGPIX® System (Luminex Corporation, USA).

RESULTS

Significantly increased concentration (p < 0.05) of three serum biomarkers (L1CAM, CA9, and HPN) were shown in mCRC when compared with primary CRC. HPN and KLK6 showed significant differences (p < 0.05) in concentration among different stages of CRC. In contrast, levels of HPN and ALDH1A1 were significantly elevated (p < 0.05) in chemotherapy-treated CRC patients as compared with nontreated ones. Conclusion: Serum biomarkers could act as a potential early CRC diagnostics test, but further additional testings are needed.

Biochemical Markers of Colorectal Cancer - Present and Future

According to a report by the National Cancer Institute, colorectal cancer (CRC) is one of the most common types of cancer worldwide. CRC is often recognized too late for successful therapy. Tumor markers have been sought for a number of years to detect the transformation of malignant cells at the earliest possible stage. They are usually proteins associated with a malignancy and might be clinically useful in patients with cancer. Several classical markers have been used to recognize colorectal cancer, including carcinoembryonic antigen (CEA), carbohydrate antigen (CA 19.9), tissue polypeptide specific antigen (TPS) and tumor-associated glycoprotein-72 (TAG-72). None of these tests, however, have excellent diagnostic accuracy. Recent studies have been conducted on the use of hematopoietic growth factors (HGFs) and various enzymes in the diagnosis and prognosis of colorectal cancer. These include macrophage-colony stimulating factor (M-CSF) and granulocyte-macrophage-colony stimulating factor (GM-CSF), interleukin-3, interleukin-6 and enzymes (alcohol dehydrogenase and lysosomal exoglycosidases). Significantly, most cancer deaths are not caused by the primary tumor itself but by its spread. Analysis of circulating cancer cells (CTCs), ie, factors responsible for metastasis, may be a source of information useful in the treatment of patients with colorectal cancer. Currently available markers have significant limitations.