Cancer cachexia: molecular mechanisms and treatment strategies.

Muscle wasting is a consequence of physiological changes or a pathology characterized by increased catabolic activity that leads to progressive loss of skeletal muscle mass and strength. Numerous diseases, including cancer, organ failure, infection, and aging-associated diseases, are associated with muscle wasting. Cancer cachexia is a multifactorial syndrome characterized by loss of skeletal muscle mass, with or without the loss of fat mass, resulting in functional impairment and reduced quality of life. It is caused by the upregulation of systemic inflammation and catabolic stimuli, leading to inhibition of protein synthesis and enhancement of muscle catabolism. Here, we summarize the complex molecular networks that regulate muscle mass and function. Moreover, we describe complex multi-organ roles in cancer cachexia. Although cachexia is one of the main causes of cancer-related deaths, there are still no approved drugs for cancer cachexia. Thus, we compiled recent ongoing pre-clinical and clinical trials and further discussed potential therapeutic approaches for cancer cachexia.

Ginsenoside Rd ameliorates muscle wasting by suppressing the signal transducer and activator of transcription 3 pathway.

BACKGROUND: The effects of some drugs, aging, cancers, and other diseases can cause muscle wasting. Currently, there are no effective drugs for treating muscle wasting. In this study, the effects of ginsenoside Rd (GRd) on muscle wasting were studied. METHODS: Tumour necrosis factor-alpha (TNF-α)/interferon-gamma (IFN-γ)-induced myotube atrophy in mouse C2C12 and human skeletal myoblasts (HSkM) was evaluated based on cell thickness. Atrophy-related signalling, reactive oxygen species (ROS) level, mitochondrial membrane potential, and mitochondrial number were assessed. GRd (10 mg/kg body weight) was orally administered to aged mice (23-24 months old) and tumour-bearing (Lewis lung carcinoma [LLC1] or CT26) mice for 5 weeks and 16 days, respectively. Body weight, grip strength, inverted hanging time, and muscle weight were assessed. Histological analysis was also performed to assess the effects of GRd. The evolutionary chemical binding similarity (ECBS) approach, molecular docking, Biacore assay, and signal transducer and activator of transcription (STAT) 3 reporter assay were used to identify targets of GRd. RESULTS: GRd significantly induced hypertrophy in the C2C12 and HSkM myotubes (average diameter 50.8 ± 2.6% and 49.9% ± 3.7% higher at 100 nM, vs. control, P ≤ 0.001). GRd treatment ameliorated aging- and cancer-induced (LLC1 or CT26) muscle atrophy in mice, which was evidenced by significant increases in grip strength, hanging time, muscle mass, and muscle tissue cross-sectional area (1.3-fold to 4.6-fold, vs. vehicle, P ≤ 0.05; P ≤ 0.01; P ≤ 0.001). STAT3 was found to be a possible target of GRd by the ECBS approach and molecular docking assay. Validation of direct interaction between GRd and STAT3 was confirmed through Biacore analysis. GRd also inhibited STAT3 phosphorylation and STAT3 reporter activity, which led to the inhibition of STAT3 nuclear translocation and the suppression of downstream targets of STAT3, such as atrogin-1, muscle-specific RING finger protein (MuRF-1), and myostatin (MSTN) (29.0 ± 11.2% to 84.3 ± 30.5%, vs. vehicle, P ≤ 0.05; P ≤ 0.01; P ≤ 0.001). Additionally, GRd scavenged ROS (91.7 ± 1.4% reduction at 1 nM, vs. vehicle, P ≤ 0.001), inhibited TNF-α-induced dysregulation of ROS level, and improved mitochondrial integrity (P ≤ 0.05; P ≤ 0.01; P ≤ 0.001). CONCLUSIONS: GRd ameliorates aging- and cancer-induced muscle wasting. Our findings suggest that GRd may be a novel therapeutic agent or adjuvant for reversing muscle wasting.

Amelioration of muscle wasting by gintonin in cancer cachexia.

Cancer cachexia is characterized by systemic inflammation, protein degradation, and loss of skeletal muscle. Despite extensive efforts to develop therapeutics, only few effective treatments are available to protect against cancer cachexia. Here, we found that gintonin (GT), a ginseng-derived lysophosphatidic acid receptor (LPAR) ligand, protected C2C12 myotubes from tumor necrosis factor α (TNFα)/interferon γ (IFNγ)- induced muscle wasting condition. The activity of GT was found to be dependent on LPAR/Gαi2, as the LPAR antagonist Ki16425 and Gαi2 siRNA abolished the anti-atrophic effects of GT on myotubes. GT suppressed TNFα-induced oxidative stress by reducing reactive oxygen species and suppressing inflammation-related genes, such as interleukin 6 (IL-6) and NADPH oxidase 2 (NOX-2). In addition, GT exhibited anti-atrophy effects in primary normal human skeletal myoblasts. Further, GT protected against Lewis lung carcinoma cell line (LLC1)-induced cancer cachexia in a mouse model. Specifically, GT rescued the lower levels of grip strength, hanging, and cross-sectional area caused by LLC1. Collectively, our findings suggest that GT may be a good therapeutic candidate for protecting against cancer cachexia.

Expression of AMP-activated protein kinase/ten-eleven translocation 2 and their clinical relevance in colorectal cancer.

Inactivation of the ten-eleven translocation (TET) family members and catalyzation of 5-methylcytosine (5-mC) into 5-hydroxymethylcytosine (5-hmC) is associated with cancer initiation and progression. AMP-activated protein kinase (AMPK) is an enzyme that stabilizes TET2; however, the clinical relevance of AMPK and TET2 expression levels is currently unclear. Therefore, the present study aimed to investigate the clinical implications of AMPK/TET2 expression levels in colorectal cancer (CRC). Immunohistochemistry was used to retrospectively examine the expression levels of AMPK and TET2 in paraffin-embedded specimens obtained from 343 patients with CRC. The results demonstrated that AMPK and TET2 were highly expressed in CRC samples. No significant association was observed between the expression levels of TET2 and patient clinicopathological characteristics (age, tumor location, lymphatic, vascular and perineural invasion, Tumor-Node-Metastasis stages and differentiation); however, patients with low expression levels of TET2 more frequently presented with distant metastasis. By contrast, the expression levels of AMPK were significantly associated with lymph node and distant metastases. The survival analysis results revealed that high expression levels of TET2 were an independent predictor of favorable prognosis compared with low TET2 levels. However, no significant differences in overall survival were observed between patients with high and low expression levels of AMPK. These results described the clinical significance of AMPK/TET2 in CRC. The results of the multivariate analysis demonstrated that high expression levels of TET2 were a predictor of a favorable prognosis, whereas AMPK was not a significant factor for determining patient prognosis; therefore, further functional analysis of AMPK/TET2 expression in CRC is needed.

AMD1 is required for the maintenance of leukemic stem cells and promotes chronic myeloid leukemic growth.

Polyamines are critical elements in mammals, but it remains unknown whether adenosyl methionine decarboxylase (AMD1), a rate-limiting enzyme in polyamine synthesis, is required for myeloid leukemia. Here, we found that leukemic stem cells (LSCs) were highly differentiated, and leukemia progression was severely impaired in the absence of AMD1 in vivo. AMD1 was highly upregulated as chronic myeloid leukemia (CML) progressed from the chronic phase to the blast crisis phase, and was associated with the poor prognosis of CML patients. In addition, the pharmacological inhibition of AMD1 by AO476 treatment resulted in a robust reduction of the progression of leukemic cells both in vitro and in vivo. Mechanistically, AMD1 depletion induced loss of mitochondrial membrane potential and accumulation of reactive oxygen species (ROS), resulting in the differentiation of LSCs via oxidative stress and aberrant activation of unfolded protein response (UPR) pathway, which was partially rescued by the addition of polyamine. These results indicate that AMD1 is an essential element in the progression of myeloid leukemia and could be an attractive target for the treatment of the disease.

microRNA-219-5p targets NEK6 to inhibit hepatocellular carcinoma progression.

MicroRNA-219-5p (miR-219-5p) is a key post-transcriptional regulator of gene expression that is known to regulate cancer progression, but its role in the context of hepatocellular carcinoma (HCC) remains to be fully elucidated. Herein, it was found that this miRNA functions as a tumor suppressor. Specifically, significant decreases in miR-219-5p expression were detected in HCC cells and patient serum samples relative to that found in the serum of 15 healthy people, and it was concluded that miR-219-5p overexpression was sufficient to impair HCC cell proliferation in vitro and vivo and migration in vitro. At the mechanistic level, it was found that miR-219-5p was able to suppress the expression of NEK6 (never in mitosis gene a-related kinase 6), thereby resulting in dysregulated ß-catenin/c-Myc-regulated gene expression. When NEK6 was overexpressed in HCC cells, this was sufficient to reverse the inhibitory impact of miR-219-5p on HCC cell proliferation both in vitro and vivo and metastasis in vitro. Bioinformatics analyses were also conducted, and both miR-219-5p and Nek6 were linked to disease progression in HCC patients with advanced disease. More importantly, the serum specimen data showed that reduced perioperative plasma miR-219-5p correlated significantly with increased risk of early recurrence after curative hepatectomy, whereas it was opposed to NEK6. Together, these findings highlight miR-219-5p as a potentially valuable diagnostic biomarker that can potentially be leveraged to improve clinical outcomes in HCC patients.

A stem cell reporter based platform to identify and target drug resistant stem cells in myeloid leukemia.

Intratumoral heterogeneity is a common feature of many myeloid leukemias and a significant reason for treatment failure and relapse. Thus, identifying the cells responsible for residual disease and leukemia re-growth is critical to better understanding how they are regulated. Here, we show that a knock-in reporter mouse for the stem cell gene Musashi 2 (Msi2) allows identification of leukemia stem cells in aggressive myeloid malignancies, and provides a strategy for defining their core dependencies. Specifically, we carry out a high throughput screen using Msi2-reporter blast crisis chronic myeloid leukemia (bcCML) and identify several adhesion molecules that are preferentially expressed in therapy resistant bcCML cells and play a key role in bcCML. In particular, we focus on syndecan-1, whose deletion triggers defects in bcCML growth and propagation and markedly improves survival of transplanted mice. Further, live imaging reveals that the spatiotemporal dynamics of leukemia cells are critically dependent on syndecan signaling, as loss of this signal impairs their localization, migration and dissemination to distant sites. Finally, at a molecular level, syndecan loss directly impairs integrin ß7 function, suggesting that syndecan exerts its influence, at least in part, by coordinating integrin activity in bcCML. These data present a platform for delineating the biological underpinnings of leukemia stem cell function, and highlight the Sdc1-Itgß7 signaling axis as a key regulatory control point for bcCML growth and dissemination.

20(R)-Ginsenoside Rg3 Influences Cancer Stem Cell Properties and the Epithelial-Mesenchymal Transition in Colorectal Cancer via the SNAIL Signaling Axis.

BACKGROUND: Cancer stem cells (CSCs) have been proposed as central drivers of cancer relapse in many cancers. In the present study, we investigated the inhibitory effect of 20(R)-Ginsenoside Rg3 (Rg3R), a major active component of ginseng saponin, on CSC-like cells and the Epithelial-Mesenchymal Transition (EMT) in colorectal cancer (CRC). METHODS: The effects of ginsenoside Rg3R on the colony-forming, migration, invasion, and wound-healing abilities of CRC cells were determined in HT29 and SW620 cell lines in vitro. Further, ginsenoside Rg3R was given intraperitoneally at 5mg/kg of mouse body weight to check its effect on the metastasis of CRC cells in vivo. RESULTS: Ginsenoside Rg3R significantly inhibited CSC properties, but did not affect cell proliferation. Moreover, ginsenoside Rg3R treatment significantly inhibited the motility of CRC cells based on migration, invasion, and wound-healing assays. The inhibitory effects of ginsenoside Rg3R on CRC are potentially mediated by significant down-regulation of the expression of stemness genes and EMT markers in CRC cells in a SNAIL-dependent manner. Furthermore, ginsenoside Rg3R treatment decreased both the number and size of tumor nodules in the liver, lung, and kidney tissues in a metastasis mouse model. CONCLUSION: These findings highlighted the potential use of ginsenoside Rg3R in clinical applications for colorectal cancer treatment.

The Role of Gut Microbiota in Intestinal Inflammation with Respect to Diet and Extrinsic Stressors.

The gut microbiota maintains a symbiotic relationship with the host and regulates several important functions including host metabolism, immunity, and intestinal barrier function. Intestinal inflammation and inflammatory bowel disease (IBD) are commonly associated with dysbiosis of the gut microbiota. Alterations in the gut microbiota and associated changes in metabolites as well as disruptions in the intestinal barrier are evidence of the relationship between the gut microbiota and intestinal inflammation. Recent studies have found that many factors may alter the gut microbiota, with the effects of diet being commonly-studied. Extrinsic stressors, including environmental stressors, antibiotic exposure, sleep disturbance, physical activity, and psychological stress, may also play important roles in altering the composition of the gut microbiota. Herein, we discuss the roles of the gut microbiota in intestinal inflammation in relation to diet and other extrinsic stressors.

miR551b Regulates Colorectal Cancer Progression by Targeting the ZEB1 Signaling Axis.

Our current understanding of the role of microRNA 551b (miR551b) in the progression of colorectal cancer (CRC) remains limited. Here, studies using both ectopic expression of miR551b and miR551b mimics revealed that miR551b exerts a tumor suppressive effect in CRC cells. Specifically, miR551b was significantly downregulated in both patient-derived CRC tissues and CRC cell lines compared to normal tissues and non-cancer cell lines. Also, miR551b significantly inhibited the motility of CRC cells in vitro, including migration, invasion, and wound healing rates, but did not affect cell proliferation. Mechanistically, miR551b targets and inhibits the expression of ZEB1 (Zinc finger E-box-binding homeobox 1), resulting in the dysregulation of EMT (epithelial-mesenchymal transition) signatures. More importantly, miR551b overexpression was found to reduce the tumor size in a xenograft model of CRC cells in vivo. Furthermore, bioinformatic analyses showed that miR551b expression levels were markedly downregulated in the advanced-stage CRC tissues compared to normal tissues, and ZEB1 was associated with the disease progression in CRC patients. Our findings indicated that miR551b could serve as a potential diagnostic biomarker and could be utilized to improve the therapeutic outcomes of CRC patients.

Defensin alpha 6 (DEFA6) is a prognostic marker in colorectal cancer.

Defensin alpha 6 (DEFA6) is a member of the alpha defensin family of microbicidal and cytotoxic peptides that defend against bacteria and viruses. Here, we provide a novel function of DEFA6 in tumorigenesis of colorectal cancer (CRC) in vitro and in vivo. Specifically, DEFA6 is highly expressed in both CRC cancer cell lines as well as patient-derived samples at the level of RNA and protein. By shRNA-mediated loss of function of DEFA6, we found that proliferation, migration, invasion, colony forming ability of CRC cell lines were impaired in the absence of DEFA6 in vitro. Furthermore, DEFA6-deficient cancer cells exhibited significantly reduced growth rates compared to control cells in vivo. More importantly, by analyzing 352 patient-derived samples, we revealed that DEFA6 is associated with overall survival rate of CRC patients and thus an independent prognostic marker for CRC. These results suggest that DEFA6 plays an essential oncogenic role in CRC and serves a good therapeutic target for the disease.

Interferon-induced transmembrane protein 1-mediated EGFR/SOX2 signaling axis is essential for progression of non-small cell lung cancer.

Emerging data indicate that interferon-induced transmembrane protein 1 (IFITM1) plays an important role in many cancers. However, it remains unclear whether IFITM1 is functionally indispensable in nonsmall cell lung cancer (NSCLC). Here, using NSCLC cell lines and patient-derived samples, we show that IFITM1 is essentially required for the progression of NSCLC in vitro and in vivo. Specifically, IFITM1 depletion resulted in a significant reduction in sphere formation, migration, and invasion of NSCLC cells in vitro; these events were inversely correlated with the ectopic expression of IFITM1. In addition, tumor development was significantly impaired in the absence of IFITM1 in vivo. Mechanistically, epidermal growth factor receptor/sex-determining region Y-box 2 (EGFR/SOX2) signaling axis was compromised in the absence of IFITM1, and the ectopic expression of SOX2 partially rescued the defects caused by IFITM1 depletion. More importantly, using 226 patient-derived samples, we demonstrate that a high level of IFITM1 expression is associated with a poor overall survival (OS) rate in adenocarcinoma but not in squamous cell carcinoma. Collectively, these data suggest that IFITM1 is a poor prognostic marker of adenocarcinoma and an attractive target to develop novel therapeutics for NSCLC.

Ginsenoside Rd Inhibits the Metastasis of Colorectal Cancer via Epidermal Growth Factor Receptor Signaling Axis.

Ginsenoside Rd is a saponin from ginseng and has been reported to have various biological activities. However, the effect of ginsenoside Rd on the metastasis of colorectal cancer (CRC) remains unknown. Here, we found that ginsenoside Rd decreased the colony-forming ability, migration, invasion, and wound-healing abilities of CRC cells, although it did not affect cell proliferation. In addition, using an inverse-docking assay, we found that ginsenoside Rd bound to epidermal growth factor receptor (EGFR) with a high binding affinity, inducing the downregulation of stemness- and epithelial-mesenchymal transition-related genes; these were partially rescued by either exogenous EGF treatment or ectopic expression of SOX2. Furthermore, ginsenoside Rd significantly decreased the number and size of tumor metastasis nodules in the livers, lungs, and kidneys of mouse model of metastasis. © 2018 IUBMB Life, 71(5):601-610, 2019.

Hedgehog Signaling in Cancer: A Prospective Therapeutic Target for Eradicating Cancer Stem Cells.

The Hedgehog (Hh) pathway is a signaling cascade that plays a crucial role in many fundamental processes, including embryonic development and tissue homeostasis. Moreover, emerging evidence has suggested that aberrant activation of Hh is associated with neoplastic transformations, malignant tumors, and drug resistance of a multitude of cancers. At the molecular level, it has been shown that Hh signaling drives the progression of cancers by regulating cancer cell proliferation, malignancy, metastasis, and the expansion of cancer stem cells (CSCs). Thus, a comprehensive understanding of Hh signaling during tumorigenesis and development of chemoresistance is necessary in order to identify potential therapeutic strategies to target various human cancers and their relapse. In this review, we discuss the molecular basis of the Hh signaling pathway and its abnormal activation in several types of human cancers. We also highlight the clinical development of Hh signaling inhibitors for cancer therapy as well as CSC-targeted therapy.

The anti-metastatic effect of ginsenoside Rb2 in colorectal cancer in an EGFR/SOX2-dependent manner.

Ginsenoside Rb2, a saponin from Panax ginseng, has been shown to have many functions. However, the effect of ginsenoside Rb2 on the metastasis of colorectal cancer (CRC) remains unknown. CRC cell lines HT29 and SW620 were used to determine the effects of ginsenoside Rb2 on the colony-forming, migration, invasion, and wound-healing abilities of CRC cells in vitro. Further, ginsenoside Rb2 was given intraperitoneally at 5 mg/kg of mouse body weight to check its effect on the metastasis of CRC cells in vivo. Ginsenoside Rb2 decreased colony-forming ability, migration, invasion, and wound healing of CRC cells in vitro, although it did not affect cell proliferation. As a possible mechanism, we found that ginsenoside Rb2 down-regulated the expression of stemness and Epithelial-mesenchymal transition (EMT)-related genes via the EGFR/SOX2 signaling axis; these were partially rescued by either exogenous EGF treatment or ectopic expression of SOX2. More importantly, ginsenoside Rb2 significantly reduced the number of metastatic nodules in the livers, lungs, and kidneys in a mouse model of metastasis. These results suggest that ginsenoside Rb2 could be used to treat the metastasis of CRC therapeutically or as a supplement.

Toll-Like Receptor 2-Mediated Suppression of Colorectal Cancer Pathogenesis by Polysaccharide A From Bacteroides fragilis.

The beneficial role of gut microbiota in intestinal diseases has been highlighted recently. Bacteroides fragilis found in the human gastrointestinal tract is a well-studied example of a beneficial bacterium that protects against intestinal inflammation. Polysaccharide A (PSA) from B. fragilis induces the production of interleukin (IL)-10 from immune cells via Toll-like receptor 2 (TLR2) signaling in animal colitis models. The direct effect of PSA on human colorectal cancer (CRC) cells has not been studied. Here, we report the effect of PSA from B. fragilis on CRC pathogenesis in SW620 and HT29 CRC cells and the molecular signaling underlying these effects. We demonstrated that PSA induced the production of the pro-inflammatory cytokine, IL-8, but not IL-10, in CRC cells. PSA inhibited CRC cell proliferation by controlling the cell cycle and impaired CRC cell migration and invasion by suppressing epithelial mesenchymal transition. Moreover, as in the case of other animal intestinal diseases, the protective role of PSA against CRC pathogenesis was also mediated by TLR2. Our results reveal that PSA from B. fragilis plays a protective role against CRC via TLR2 signaling.

Melatonin and 5-fluorouracil co-suppress colon cancer stem cells by regulating cellular prion protein-Oct4 axis.

Melatonin suppresses tumor development. However, the exact relationship between melatonin and cancer stem cells (CSCs) is poorly understood. This study found that melatonin inhibits colon CSCs by regulating the PrPC -Oct4 axis. In specimens from patients with colorectal cancer, the expressions of cellular prion protein (PrPC ) and Oct4 were significantly correlated with metastasis and tumor stages. Co-treatment with 5-fluorouracil (5-FU) and melatonin inhibited the stem cell markers Oct4, Nanog, Sox2, and ALDH1A1 by downregulating PrPC . In this way, tumor growth, proliferation, and tumor-mediated angiogenesis were suppressed. In colorectal CSCs, PRNP overexpression protects Oct4 against inhibition by 5-FU and melatonin. In contrast, Nanog, Sox2, and ALDH1A1 have no such protection. These results indicate that PrPC directly regulates Oct4, whereas it indirectly regulates Nanog, Sox2, and ALDH1A1. Taken together, our findings suggest that co-treatment with anticancer drug and melatonin is a potential therapy for colorectal cancer. Furthermore, PrPC maintains cancer stemness during tumor progression. Therefore, targeting the PrPC -Oct4 axis may prove instrumental in colorectal cancer therapy.

Cancer Stem Cells (CSCs) in Drug Resistance and their Therapeutic Implications in Cancer Treatment.

Cancer stem cells (CSCs), also known as tumor-initiating cells (TICs), are suggested to be responsible for drug resistance and cancer relapse due in part to their ability to self-renew themselves and differentiate into heterogeneous lineages of cancer cells. Thus, it is important to understand the characteristics and mechanisms by which CSCs display resistance to therapeutic agents. In this review, we highlight the key features and mechanisms that regulate CSC function in drug resistance as well as recent breakthroughs of therapeutic approaches for targeting CSCs. This promises new insights of CSCs in drug resistance and provides better therapeutic rationales to accompany novel anticancer therapeutics.

Protein kinase, membrane­associated tyrosine/threonine 1 is associated with the progression of colorectal cancer.

The protein kinase, membrane­associated tyrosine/threonine 1 (PKMYT1) is known to inhibit precocious entry into mitosis by phosphorylating CDK1 at Thr14 and Tyr15 residues. However, the functional importance of PKMYT1 in colorectal cancer (CRC) remains unknown. Thus, it is important to elucidate whether PKYMT1 is indispensable in the tumorigenesis of CRC. To investigate the functional importance of PKMYT1 in CRC tumorigenesis, PKMYT1 was knocked down in CRC cell lines such as SW480, SW620, HCT116 and HT29 by siRNA. PKMYT1­depleted CRC cells were analyzed to determine proliferation, migration, invasion and colony forming ability. In addition, 179 patient­derived samples were used to find the correlation of the expression of PKMYT1 with the prognosis of CRC patients. By siRNA­mediated loss of function of PKMYT1, we observed that proliferation, migration, invasion and colony forming ability of CRC cell lines were significantly impaired in the absence of PKMYT1 in vitro. Furthermore, by analyzing patient­derived samples, we revealed the association of PKMYT1 with the overall survival rate of CRC patients. These results indicated that PKMYT1 plays an essential oncogenic role in CRC and could serve as a good therapeutic target for the treatment of CRC.

Karyopherin α-2 is a reliable marker for identification of patients with high-risk stage II colorectal cancer.

PURPOSE: Adjuvant chemotherapy (AC) is frequently considered in patients with high-risk stage II colorectal cancer (CRC). Among patients with stage II CRC who do not receive AC because they are not considered to be at high risk, 20-25% will develop recurrence and die from the disease. Elevated levels of KPNA2 have been observed in various cancers, and overexpression of KPNA2 is related to CRC progression. METHODS: We examined the expression of KPNA2 using 293 CRC tissues, including 118 with stage II CRC, and investigated the applicability of KPNA2 as a biomarker to predict high-risk stage II CRC. Moreover, we further investigated the role of KPNA2 as an oncogene in CRC carcinogenesis using in vitro functional studies. RESULTS: High KPNA2 expression was associated with vascular (p = 0.027) and lymphatic invasion (p = 0.009) in patients with stage II CRC. On multivariate analysis, high KPNA2 expression (HR 3.174, 95% CI 2.060-4.889; p < 0.001) was independently associated with survival in patients with CRC. The overall survival rate in patients with high KPNA2 expression was higher than that in patients with low KPNA2 expression in CRC (p < 0.001), even in patients with stage II CRC (p = 0.001). Additionally, KPNA2 was associated with tumorigenesis and cancer progression in CRC cells; high KPNA2 expression was associated with increased cell proliferation (p < 0.05), migration (p = 0.03), invasion (p = 0.001), and semisolid agar colony formation (p < 0.001). CONCLUSION: KPNA2 expression is useful for identification of patients with high-risk stage II CRC who could benefit from AC and that KPNA2 may also be a promising therapeutic target.