mRNA expression of IGF-1 and IGF-1R in patients with colorectal adenocarcinoma and type 2 diabetes

Correlation of serum IGF-1, AGEs and their receptors with the risk of colorectal cancer in patients with type 2 diabetes mellitus

Background

According to epidemiological evidence, people with type 2 diabetes mellitus have a higher risk of developing colorectal cancer.

Objective

To examine the relationship between colorectal cancer (CRC) and serum levels of IGF-1, IGF-1R, AGEs,RAGE and sRAGE in patients with type 2 diabetes.

Methods

By using RNA-Seq data of CRC patients from The Cancer Genome Atlas (TCGA) database, we divided the patients into normal group(58 patients)and tumor group(446 patients), and analyzed the expression and prognostic value analysis of IGF-1,IGF1R and RAGE. Cox regression and the Kaplan-Meier method were used to determine the predictive value of target gene on clinical outcomes in CRC patients. In order to further combine CRC with diabetes research,one hundred forty-eight patients hospitalized in the Second Hospital of Harbin Medical University from July 2021 to July 2022 were enrolled and divided into CA and control groups. There were 106 patients in the CA group, including 75 patients with CRC and 31 patients with CRC+T2DM; the control group comprised 42 patients with T2DM. Circulating levels of IGF-1, IGF-1R, AGEs, RAGE, and sRAGE in the serum of the patients were measured using Enzyme-Linked Immunosorbnent Assay (ELISA) kits, and other clinical parameters were also measured during hospitalization. Statistical methods used were χ² test, independent samples t-test and Pearson correlation analysis were. Finally, we controlled for confounding factors and used logistic multi-factor regression analysis.

Results

Bioinformatics analysis showed that IGF-1, IGF1R and RAGE were highly expressed in CRC patients, and the patients with high expression also showed significantly lower overall survival rate. Through Cox regression analysis, IGF-1 can be used as an independent influencing factor of CRC. In the ELISA experiment, serum AGE, RAGE, IGF-1, and IGF-1R levels were higher in the CRC and CRC+T2DM groups than in the T2DM group, but the serum sRAGE concentrations in these groups were lower than those in the T2DM group (P < 0.05). Serum AGE, RAGE, sRAGE, IGF1, and IGF1R levels were higher in the CRC+T2DM group than in the CRC group (P < 0.05). In CRC+T2DM patients, serum AGEs were correlated with age (p = 0.027), and the serum AGE levels in these groups were positively correlated with RAGE and IGF-1 levels (p < 0.001) and negatively correlated with sRAGE and IGF-1R levels (p < 0.001). After correcting for confounding factors based on logistic multiple regression analysis, the effects of age, serum IGF-1 and IGF-1R on the development of CRC in patients with T2DM were statistically significant (p<0.05).

Conclusion

Serum IGF-1 and IGF-1R levels independently influenced the development of CRC in patients with T2DM. Furthermore, IGF-1 and IGF-1R were correlated with AGEs in CRC patients who also had T2DM, suggesting that AGEs may influence the development of CRC in T2DM patients. These findings suggest that we may be able to lower the risk of CRC in the clinic by regulating AGEs through the regulation of blood glucose levels, which will affect IGF-1 and its receptors.

Impaired Glucose Metabolism, Anti-Diabetes Medications, and Risk of Thyroid Cancer

Simple Summary

An epidemiologic link exists between obesity, insulin resistance, diabetes, and some cancers, such as breast cancer and colon cancer. The prevalence of obesity and diabetes is increasing, and additional epidemiologic data suggest that there may be a link between obesity and risk of thyroid abnormalities. Factors that may link obesity and diabetes with thyroid proliferative disorders include elevated circulating levels of insulin, increased body fat, high blood sugars, and exogenous insulin use. However, mechanisms underlying associations of obesity, diabetes, and thyroid proliferative disorders are not yet fully understood. The present manuscript reviews and summarizes current evidence of mechanisms and epidemiologic associations of obesity, insulin resistance, and use of anti-diabetes medications with benign and malignant proliferative disorders of the thyroid.

Abstract

The prevalence of obesity is progressively increasing along with the potential high risk for insulin resistance and development of type 2 diabetes mellitus. Obesity is associated with increased risk of many malignancies, and hyperinsulinemia has been proposed to be a link between obesity and cancer development. The incidence of thyroid cancer is also increasing, making this cancer the most common endocrine malignancy. There is some evidence of associations between obesity, insulin resistance and/or diabetes with thyroid proliferative disorders, including thyroid cancer. However, the etiology of such an association has not been fully elucidated. The goal of the present work is to review the current knowledge on crosstalk between thyroid and glucose metabolic pathways and the effects of obesity, insulin resistance, diabetes, and anti-hyperglycemic medications on the risk of thyroid cancer development.

Insulin-Like Growth Factor 1 (IGF-1) Signaling in Glucose Metabolism in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common aggressive carcinoma types worldwide, characterized by unfavorable curative effect and poor prognosis. Epidemiological data re-vealed that CRC risk is increased in patients with metabolic syndrome (MetS) and its serum components (e.g., hyperglycemia). High glycemic index diets, which chronically raise post-prandial blood glucose, may at least in part increase colon cancer risk via the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway. However, the underlying mechanisms linking IGF-1 and MetS are still poorly understood. Hyperactivated glucose uptake and aerobic glycolysis (the Warburg effect) are considered as a one of six hallmarks of cancer, including CRC. However, the role of insulin/IGF-1 signaling during the acquisition of the Warburg metabolic phenotypes by CRC cells is still poorly understood. It most likely results from the interaction of multiple processes, directly or indirectly regulated by IGF-1, such as activation of PI3K/Akt/mTORC, and Raf/MAPK signaling pathways, activation of glucose transporters (e.g., GLUT1), activation of key glycolytic enzymes (e.g., LDHA, LDH5, HK II, and PFKFB3), aberrant expression of the oncogenes (e.g., MYC, and KRAS) and/or overexpression of signaling proteins (e.g., HIF-1, TGF-β1, PI3K, ERK, Akt, and mTOR). This review describes the role of IGF-1 in glucose metabolism in physiology and colorectal carcinogenesis, including the role of the insulin/IGF system in the Warburg effect. Furthermore, current therapeutic strategies aimed at repairing impaired glucose metabolism in CRC are indicated.

Engineering of diseased human skin equivalent using 3D cell printing for representing pathophysiological hallmarks of type 2 diabetes in vitro

Despite many significant advances in 3D cell printing for skin, a disease model displaying the pathological processes present in the native skin has not been reported yet. Therefore, we were motivated for modeling a 3D diseased skin tissue with pathophysiological hallmarks of type 2 diabetes in vitro based on 3D cell printing technique. By stimulating epidermal-dermal intercellular crosstalk found in the native skin, it was hypothesized that normal keratinocytes would be differentiated as diabetic epidermis when interacting with the diabetic dermal compartment. To prove this, a novel wounded skin model was successfully devised during tissue maturation in vitro. Interestingly, the slow re-epithelization was observed in our diabetic model, which is a representative hallmark of diabetic skin. Using the versatility of 3D cell printing, the structural similarities and diabetic properties of the model were further augmented by addition of perfusable vascularized diabetic hypodermis. Insulin resistance, adipocyte hypertrophy, inflammatory reactions, and vascular dysfunction, as the typical hallmarks in diabetes, were found under hyperglycemia. Finally, the feasibility of this new disease model for drug development was successfully demonstrated through application of test drugs. We trust that this study provides a pioneering step towards 3D cell printing-based in vitro skin disease modeling.

High IGF1R protein expression correlates with disease-free survival of patients with stage III colon cancer

PURPOSE

The aim of this study was to investigate the association between expression of insulin-like growth factor-1 receptor (IGF1R) and its ligand, IGF-II, and disease-free survival (DFS) in patients with stage III colon cancer (CC).

METHODS

In this retrospective study we included consecutive patients who underwent curative surgery for stage III CC. IGF1R and IGF-II/IGF2 status were evaluated in tumour samples by immunohistochemistry and quantitative real-time PCR (qRT-PCR). Associations of markers with DFS were analysed using Cox proportional hazards models.

RESULTS

Hundred and fifty-one CC patients were included (median age, 66.6 years; female, 54.3%). Low levels of IGF1R and IGF-II protein expression were observed in 16.1% and 10.7% of the cases, respectively. No significant differences in clinicopathological characteristics between patients with tumours expressing low IGF1R or IGF-II protein levels and those with high levels were observed. A low IGF1R protein expression was found to be significantly associated with a shorter DFS (HR 3.32; 95% CI, 1.7-6.31; p = 0.0003), while no association was observed between IGF-II protein expression and DFS (HR 0.91; 95% CI, 0.28-2.96; p = 0.87). In a multivariate analysis, IGF1R protein status remained an independent prognostic factor for DFS (HR 2.73; 95% CI, 1.40-5.31; p = 0.003). Furthermore, we found that neither IGF1R nor IGF2 mRNA expression levels as measured by qRT-PCR correlated with the respective protein expression levels as assessed by immunohistochemistry. Neither of the mRNA expression levels was significantly associated with DFS.

CONCLUSIONS

From our data we conclude that low IGF1R protein expression represents a poor prognostic biomarker in stage III colon cancer.

Thyroid Abnormalities in Patients With Extreme Insulin Resistance Syndromes

CONTEXT

Insulin and leptin may increase growth and proliferation of thyroid cells, underlying an association between type 2 diabetes and papillary thyroid cancer (PTC). Patients with extreme insulin resistance due to lipodystrophy or insulin receptor mutations (INSR) are treated with high-dose insulin and recombinant leptin (metreleptin), which may increase the risk of thyroid neoplasia.

OBJECTIVE

The aim of this study was to analyze thyroid structural abnormalities in patients with lipodystrophy and INSR mutations and to assess whether insulin, IGF-1, and metreleptin therapy contribute to the thyroid growth and neoplasia in this population.

DESIGN

Thyroid ultrasound characteristics were analyzed in 81 patients with lipodystrophy and 11 with INSR (5 homozygous; 6 heterozygous). Sixty patients were taking metreleptin.

RESULTS

The prevalence of thyroid nodules in children with extreme insulin resistance (5 of 30, 16.7%) was significantly higher than published prevalence for children (64 of 3202; 2%), with no difference between lipodystrophy and INSR. Body surface area-adjusted thyroid volume was larger in INSR homozygotes vs heterozygotes or lipodystrophy (10.4 ± 5.1, 3.9 ± 1.5, and 6.2 ± 3.4 cm2, respectively. Three patients with lipodystrophy and one INSR heterozygote had PTC. There were no differences in thyroid ultrasound features in patients treated vs not treated with metreleptin.

CONCLUSION

Children with extreme insulin resistance had a high prevalence of thyroid nodules, which were not associated with metreleptin treatment. Patients with homozygous INSR mutation had thyromegaly, which may be a novel phenotypic feature of this disease. Further studies are needed to determine the etiology of thyroid abnormalities in patients with extreme insulin resistance.

Changes of serum IGF-1 and ET-1 levels in patients with osteoporosis and its clinical significance

Objective:

To investigate the correlations of levels of serum insulin-like growth factor-1 (IGF-1) and endothelin-1 (ET-1) with cytokines including interleukin (IL)-18, IL-6 and high-sensitivity C-reactive protein (hs-CRP) and bone material density in patients with osteoporosis d.

Methods:

Eighty patients with osteoporosis who were treated in our hospital from April 2016 to October 2017 were selected as observation group, and 60 healthy elderly people who received physical examination in our hospital in the same period were selected as control group. The serum levels of IGF-1 and ET-1 were detected using enzyme-linked immunosorbent assay. The bone material density of the lumbar vertebra, tibial neck and Ward’s triangle of every research subject was measured using dual-energy x-rays absorptiometry. The correlations between variables were analyzed using Pearson correlation analysis.

Results:

The level of IGF-1 in the observation group was lower than that in the control group, and the level of ET-1 in the observation group was higher than that in the control group (P<0.05). The levels of interleukin (IL)-18, IL-6 and high-sensitivity C-reactive protein (hs-CRP) in the observation group were significantly higher than those in the control group (P<0.05). Bone mineral density of lumbar vertebra, tibial neck and Ward triangle in the observation group was significantly lower than that in the control group (P<0.05); the IGF-1 level of osteoporosis patients was negatively correlated with IL-18, IL-6, hs-CRP levels and positively correlated with bone mineral density; the ET-1 level was positively correlated with IL-18, IL-6, hs-CRP levels and negatively correlated with bone mineral density.

Conclusion:

Patients with osteoporosis have decreased level of IGF-1 but increased level of ET-1, and they are closely related to cytokines and bone mineral density and may participate in the pathogenesis of osteoporosis.

Associations of dinner-to-bed time, post-dinner walk and sleep duration with colorectal cancer: A case-control study

Colorectal cancer (CRC) ranked 3rd for cancer incidence and 4th for cancer death worldwide. Despite the increasing number of CRC studies, the etiology is not yet clear. In this study, we investigated the effects of the dinner-to-bed time, post-dinner walk and sleep duration on the risk for CRC.We conducted a matched case-control study based on hospital population. We involved 166 patients had a newly histologically confirmed CRC without previous treatment and 166 healthy healthy residents matched by age and gender at Fujian Medical Union Hospital. A self-designed questionnaire was used to information on demographic characteristics, dinner-to-bed time, post-dinner walk, sleep duration, and other behavioral factors. Conditional logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (95% CIs) to assess the effect of dinner-to-bed time, post-dinner walking, and sleep duration as well as their joint effect on the risk of CRC at different genders.The adjusted odds ratio (AOR) of CRC for subjects with shorter dinner-to-bed time (2.0-2.9 h) were 2.527 (95% CIs = 1.127-5.337), relative to those with longer dinner-to-bed time (≥4 h), the difference was statistically significant (P < .05). Post-dinner walk was associated with a significantly decreased CRC risk (AOR = 0.339, 95% CIs = 0.203-0.865) compared with post-dinner non-walk. Compared with 6-9 h of sleep duration, the risk OR of CRC were 3.843 (95% CIs = 2.767-7.800, P < .05) and 2.12 (95% CIs = 0.754-5.959, P > .05) for long (≥9 h) and short (<6 h) sleep duration. The risk of CRC individuals with shorter dinner-to-bed time and post-dinner non-walk caused higher risk than those with longer dinner-to-bed time and post-dinner walk (AOR = 3.361, 95% CIs = 2.043-6.316). The risk of CRC was 2.231 (95% CIs = 1.089-3.762, P < .001), with a shorter dinner-to-bed time and ≥9 hours of sleep duration.We found that shorter dinner-to-bed time (<3 h), post-dinner walk, and long sleep duration (≥9 h) were seems to be related to CRC and may increase the risk of CRC.

Effects of β-caryophyllene on arginine ADP-ribosyltransferase 1-mediated regulation of glycolysis in colorectal cancer under high-glucose conditions

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of the development of colorectal cancer (CRC). A previous study revealed that the levels of arginine-specific mono-ADP-ribosyltransferase 1 (ART1) in CRC tissues from patients with T2DM were higher than in non-diabetic patients. Hyperglycemia, which is a risk factor of cancer, is a common feature of T2DM; however, the effects of ART1 on glycolysis and energy metabolism in CRC cells under high-glucose conditions remains to be elucidated. β-caryophyllene (BCP) has been reported to exert anticancer and hypoglycemic effects. In the present study, CT26 cells were cultured under a high-glucose conditions and the expression levels of relevant factors were detected by western blotting. Cell Counting Kit-8 assay, flow cytometry, Hoechst 33258 staining, ATP assay and lactic acid assay were used to detect the proliferation, apoptosis and energy metabolism of CT26 cells. To observe the effects of ART1 and BCP on tumor growth in vivo, CT26 cell tumors were successfully transplanted into BALB/c mice with T2DM. The results demonstrated that overexpression of ART1 may increase glycolysis and energy metabolism in CT26 CRC cells under high glucose conditions by regulating the protein kinase B/mammalian target of rapamycin/c‑Myc signaling pathway and the expression of glycolytic enzymes. BCP inhibited the effects induced by ART1, which may be due to a BCP-induced reduction in the expression levels of ART1 via nuclear factor-κB. Therefore, ART1 may be considered a therapeutic target for the treatment of diabetic patients with CRC.

Myotubularin-related protein 7 inhibits insulin signaling in colorectal cancer

Phosphoinositide (PIP) phosphatases such as myotubularins (MTMs) inhibit growth factor receptor signaling. However, the function of myotubularin-related protein 7 (MTMR7) in cancer is unknown. We show that MTMR7 protein was down-regulated with increasing tumor grade (G), size (T) and stage (UICC) in patients with colorectal cancer (CRC) (n=1786). The presence of MTMR7 in the stroma correlated with poor prognosis, whereas MTMR7 expression in the tumor was not predictive for patients' survival. Insulin reduced MTMR7 protein levels in human CRC cell lines, and CRC patients with type 2 diabetes mellitus (T2DM) or loss of imprinting (LOI) of insulin-like growth factor 2 (IGF2) had an increased risk for MTMR7 loss. Mechanistically, MTMR7 lowered PIPs and inhibited insulin-mediated AKT-ERK1/2 signaling and proliferation in human CRC cell lines. MTMR7 provides a novel link between growth factor signaling and cancer, and may thus constitute a potential marker or drug target for human CRC.

Expression characteristics of proteins of IGF-1R, p-Akt, and survivin in papillary thyroid carcinoma patients with type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is related to increased risk of papillary thyroid carcinoma (PTC). Insulin-like growth factor-1 receptor (IGF-1R) is increased in patients with T2DM. The increased IGF-1R may be responsible for the development of PTC. In this study, we investigated the expression of phosphorylation of Akt (p-Akt)/survivin pathway activated by IGF-1R in PTC subjects with and without diabetes.Clinicopathological data of 20 PTC patients with T2DM were retrospectively analyzed and compared with those of 21 PTC subjects without diabetes. Meanwhile, IGF-1R, p-Akt, and survivin expressions of PTC tissues were detected by immunohistochemical staining.The immunohistochemical results found that the expression level of IGF-1R was significantly higher in diabetic PTC patients than that in nondiabetic PTC patients (P < 0.05). However, no significant differences of p-Akt and survivin expression were found between PTC patients with T2DM and PTC patients without T2DM. In addition, among 20 PTC patients with T2DM, subgroup analysis showed that the ratio of tumor size >10 mm was significantly higher in IGF-1R moderate to strong expression group than that in IGF-1R negative to weak expression group (P < 0.05).IGF-1R expression level was higher in PTC patients with T2DM, and the increased IGF-1R expression was associated with lager tumor size. IGF-1R may play an important role in carcinogenesis and tumor growth in PTC patients with T2DM.

Higher Expression of Proteins in IGF/IR Axes in Colorectal Cancer is Associated with Type 2 Diabetes Mellitus

Preexisting type 2 diabetes mellitus (preDM) increases occurrence and mortality of colorectal cancer (CRC). Insulin growth factor (IGF)/insulin receptor (IR) axes play an important role in the development of both diabetes and CRC. We aimed to explore the characteristics of proteins expression in IGF/IR axes in CRC tissues with preDM. Two hundred fifty CRC patients in West China hospital were included in analysis. Among them, 125 patients had history of diabetes matched by 125 CRC without diabetes at a 1:1 ratio. Immunohistochemical staining was used to detect the expression of proteins in IGF/IR axis. More positive expression of IGF-1, IGF-1R and IR were found in CRC group with diabetes than in non-diabetes group. No difference was detected in the expression of IR substrate-1, IR substrate-2, IGF-2, IGF binding protein 3, and mammalian target of rapamycin between two groups. Multivariate analysis showed that diabetes history was associated with all of the expression of IGF-1, IGF-1R and IR, and higher T staging and lymph node metastasis were respectively independent factors of IGF-1 and IGF-1R expression in CRC patients. Besides, IGF-1 expression was positively associated with IGF-1R and IR expression in all CRC tissues, and the association of IGF-1 and IR expression seemed to be closer in diabetes group than in non-diabetes group. Higher expression of IGF-1, IGF-1R and IR proteins in CRC was associated with diabetes, suggesting IGF-1/IR signaling may play a special part in development of CRC in patients with diabetes.

Obesity and intestinal epithelial deletion of the insulin receptor, but not the IGF 1 receptor, affect radiation-induced apoptosis in colon

Current views suggest that apoptosis eliminates genetically damaged cells that may otherwise form tumors. Prior human studies link elevated insulin and reduced apoptosis to risk of colorectal adenomas. We hypothesized that hyperinsulinemia associated with obesity would lead to reduced colon epithelial cell (CEC) apoptosis after radiation and that this effect would be altered by deletion of the insulin-like growth factor (IGF) 1 receptor (IGF1R) or the insulin receptor (IR). Mice with villin-Cre-mediated IGF1R or IR deletion in CECs and floxed littermates were fed a high-fat diet to induce obesity and hyperinsulinemia or control low-fat chow. Mice were exposed to 5-Gy abdominal radiation to induce DNA damage and euthanized 4 h later for evaluation of apoptosis by localization of cleaved caspase-3. Obese mice exhibited decreased apoptosis of genetically damaged CECs. IGF1R deletion did not affect CEC apoptosis in lean or obese animals. In contrast, IR loss increased CEC apoptosis in both diet groups but did not prevent antiapoptotic effects of obesity. Levels of p53 protein were significantly reduced in CECs of obese mice with intact IR but increased in both lean and obese mice without IR. Levels of mRNAs encoding proapoptotic Perp and the cell cycle inhibitor Cdkn1b/p27 were reduced in CECs of obese mice and increased in lean mice lacking IR. Together, our studies provide novel evidence for antiapoptotic roles of obesity and IR, but not IGF1R, in colonic epithelium after DNA damage. However, neither IR nor IGF1R deletion prevented a reduction in radiation-induced CEC apoptosis during obesity and hyperinsulinemia.

Nonalcoholic fatty liver disease: a negative risk factor for colorectal cancer prognosis

Nonalcoholic fatty liver disease (NAFLD) is known to be associated with an increased risk of colorectal cancer (CRC). However, the relationship between NAFLD and the prognosis of CRC remains unclear. The primary objective of this study was to evaluate the overall survival (OS) and disease-free survival (DFS) rates in patients with CRC and the secondary objective was to compare clinicopathologic variables which were stratified by NAFLD. We performed a large cohort study of 1314 patients who were first diagnosed with CRC between January 2006 and April 2011. Postoperative follow-up data were collected from out-patient medical records, telephone consultations, and social security death indices. The Kaplan-Meier method was used to calculate the cumulative survival rate. Clinicopathologic variables were analyzed by univariate analysis and multivariate analysis through a Cox proportional hazard regression model. The mean follow-up time was 52.7 ± 25.3 months. Upon baseline comparison, the NAFLD group had significantly higher values of body mass index, triglycerides, and uric acid and significantly lower values of high-density lipoprotein, compared with the non-NAFLD group (P < 0.05 for all). There were no significant differences between the 2 groups with regard to tumor location, TNM staging, tumor differentiation, carcinoembryonic antigen, and vascular invasion. The cumulative 1-, 3-, and 5-year OS rates were 96.1%, 85.2%, and 80.6%, respectively, in the NAFLD group, which were statistically significantly higher than the OS rates of 91.6%, 76.2%, and 67.8%, respectively, in the non-NAFLD group (P = 0.075, P = 0.002, P = 0.030, respectively). There was no difference in DFS rates between the CRC patients with and without NAFLD (P = 0.267). Multivariate analysis showed that the presence of NAFLD was an independent negative risk factor for OS after adjusting for clinicopathologic covariates (hazard ratio = 0.593; 95% confidence interval 0.442, 0.921; P = 0.020), but not for DFS (P = 0.270). NAFLD may play a protective role in OS for CRC patients. Further studies are needed to elucidate the molecular mechanisms of putative protective effects in CRC patients with NAFLD.

Characterization of cathepsin X in colorectal cancer development and progression

The lysosomal cysteine carboxypeptidase cathepsin X (CTSX), localized predominantly in immune cells, has been associated with the development and progression of cancer. To determine its specific role in colorectal carcinoma (CRC), we analyzed CTSX expression in non-malignant mucosa and carcinoma of 177 patients as well as in 111 adenomas and related it with clinicopathological parameters. Further, the role of CTSX in the adhesion and invasion of the colon carcinoma cell lines HT-29 and HCT116 was investigated in an in vitro culture cell system with fibroblasts and monocytes, reflecting the situation at the tumor invasion front. Epithelial CTSX expression significantly increased from normal mucosa to adenoma and carcinoma, with highest expression levels in high grade intraepithelial neoplasia and in early tumor stages. Loss of CTSX occurred with tumor progression, and correlated with advanced local invasion, lymph node and distal metastasis, lymphatic vessel and vein invasion, tumor cell budding and poorer overall survival of patients with CRC. The subcellular distribution of CTSX changed from vesicular paranuclear expression in the tumor center to submembranous expression in cells of the invasion front. Peritumoral macrophages showed highest expression of CTSX. In vitro assays identified CTSX as relevant factor for cell-cell adhesion and tumor cell anchorage to fibroblasts and basal membrane components, whereas inhibition of CTSX caused increased invasiveness of colon carcinoma cells in mono- and co-culture. In conclusion, CTSX is involved in early tumorigenesis and in the stabilization of tumor cell formation in CRC. The results suggest that loss of CTSX may be needed for tumor cell detachment, local invasion and tumor progression. In addition, CTSX in tumor-associated macrophages indicates a role for CTSX in the anti-tumor immune response.