SELE gene as a characteristic prognostic biomarker of colorectal cancer

OBJECTIVE

To investigate the expression and clinical value of the E-selectin gene (SELE) in colorectal cancer (CRC).

METHODS

Using gene expression profiles and clinicopathological data for patients with CRC from The Cancer Genome Atlas, and tumor and adjacent normal tissues from 31 patients with CRC from Xianyang Central Hospital, we studied the correlation between SELE gene expression and clinical parameters using Kaplan-Meier and Cox proportional hazards regression analyses.

RESULTS

Higher expression of SELE was significantly associated with a poorer prognosis and shorter survival in patients with CRC. The median expression level of SELE was significantly higher in CRC tissues compared with healthy adjacent tissue. Cox regression analysis showed that the prognosis of CRC was significantly correlated with the expression of SELE. Immunohistochemical analysis also showed that positive expression of E-selectin increased significantly in line with increasing TNM stage.Conclusion: This study confirmed that SELE gene expression is an independent prognostic factor in patients with CRC.

Platelets in aging and cancer-"double-edged sword"

Platelets control hemostasis and play a key role in inflammation and immunity. However, platelet function may change during aging, and a role for these versatile cells in many age-related pathological processes is emerging. In addition to a well-known role in cardiovascular disease, platelet activity is now thought to contribute to cancer cell metastasis and tumor-associated venous thromboembolism (VTE) development. Worldwide, the great majority of all patients with cardiovascular disease and some with cancer receive anti-platelet therapy to reduce the risk of thrombosis. However, not only do thrombotic diseases remain a leading cause of morbidity and mortality, cancer, especially metastasis, is still the second cause of death worldwide. Understanding how platelets change during aging and how they may contribute to aging-related diseases such as cancer may contribute to steps taken along the road towards a "healthy aging" strategy. Here, we review the changes that occur in platelets during aging, and investigate how these versatile blood components contribute to cancer progression.

The potential of hypericin and hyperforin for antiadhesion therapy to prevent metastasis of parental and oxaliplatin-resistant human adenocarcinoma cells (HT-29)

Cancer cells disseminate to other parts of the body during metastasis through the process of intravasation. The hypericin and hyperforin effect has been described to understand the signal mechanisms that stimulate or stunt cancer cell sprouting to metastasis on colon adenocarcinoma cells HT-29 and its resistant form HT-29-OxR. We focused on the key points of adhesion proteins (cadherin, integrin, selectin and syndecan) and also proteins participating in or contributing to the process of cancer cell migration and adhesion through genes expression and proteins levels. Treatment effects were identified as a consequence of decreased cell adhesion, changes of expression in the adhesive proteins as well as basal membrane degradation associated with changes in the expression of matrix proteinases and in their activity. Finally, the cells affected by hypericin or hyperforin were evaluated by monitoring the cancer cell adhesion properties and proliferation processes. Supplementary Fig. (Supplemental digital content 1, http://links.lww.com/ACD/A267).

Clinical Significance of Serum Carcinoembryonic Antigen and Carbohydrate Antigen 19-9 Levels Before Surgery and During Postoperative Follow-Up in Colorectal Cancer

Objective:

Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are the most common colorectal cancer markers. We aimed to identify the appropriate clinical conditions for measuring serum CEA and CA19-9 levels before surgery and during follow-up.

Methods:

This study included 1275 colorectal cancer patients who were divided into 3 groups according to preoperative CEA levels (group A, ≤5 ng/mL; group B, >5–≤11 ng/mL; group C, >11 ng/mL). Each group was subdivided into 2 groups according to preoperative CA19-9 levels (cutoff level: ≤37 U/mL). Recurrence and survival rates were analyzed.

Results:

Recurrence rate, disease-free survival after curative surgery, and prognosis were significantly worse in group A and B patients with high CA19-9 levels. At recurrence, CEA levels showed a greater increase in group B and C patients; CA19-9 levels increased in group A patients with high CA19-9 levels. At recurrence, high serum CA19-9 levels were observed in group A patients with high preoperative serum CA19-9 levels, even if the serum CEA level did not increase. Preoperative CA19-9 levels could predict recurrence and prognosis in groups A and B.

Conclusion:

Periodic CA19-9 determination is useful for monitoring recurrence among group A patients with high CA19-9 levels.

Serum carbohydrate antigen 19-9 in pancreatic adenocarcinoma: a mini review for surgeons

The optimal management of oncological conditions is reflected by the careful interpretation of investigations for screening, diagnosis, staging, prognostication and surveillance. Serum tumour markers are examples of commonly requested tests in conjunction with other imaging and endoscopic tests that are used to help clinicians to stratify therapeutic decisions. Serum carbohydrate antigen 19-9 (CA19-9) is a key biomarker for pancreatic cancers. Although this biomarker is considered clinically useful and informative, clinicians are often challenged by the accurate interpretation of elevated serum CA19-9 levels. Recognizing the pitfalls of normal and abnormal serum CA19-9 concentrations will facilitate its appropriate use. In this review, we appraised the biomarker, serum CA19-9, and highlighted the clinical utility and limitations of serum CA19-9 in the investigation and management of pancreatic cancers.

The prognostic value of serum CA 19-9 for patients with advanced lung adenocarcinoma

Background

This study aimed to assess the prognostic accuracy of serum CA 19-9 in patients with advanced lung adenocarcinoma.

Methods

We retrospectively reviewed data of 246 patients who were diagnosed at our institute with advanced (stage IIIB or IV) lung adenocarcinoma between March 2006 and December 2012. We excluded patients who received no chemotherapy, or for whom we had no data on pre-treatment tumor markers. We also evaluated 116 consecutive resected specimens from patients with clinical stage I lung adenocarcinoma pathologically.

Results

The 76 (31 %) patients who were CA 19-9⁺ had shorter overall survival (OS) than CA 19-9⁻ group (12.5 vs 26.2 months, P = 0.005). Cox’s multivariate regression analysis identified Eastern Cooperative Oncology Group Performance Status 0 or 1 (P < 0.001), mutated epidermal growth factor receptor (EGFR) status (P < 0.001), stage IIIB (P < 0.001), CYFRA 21-1⁻ (P < 0.001), CA 19-9⁻ (P = 0.005) and use of platinum doublet therapy (P = 0.034) as independent predictors of longer OS. We stratified patients by CA 19-9 and CYFRA 21-1 as double positive (CA 19-9⁺/CYFRA 21-1⁺, n = 59), single positive (either CA19-9⁺ or CYFRA 21-1⁺, n = 113), or double negative (CA 19-9⁻/CYFRA 21-1⁻, n = 74). Their respective OS were 10.0, 23.3 and 31.8 months (P < 0.001). Pathological analysis also correlated CA 19-9 expression with malignant features such as vessel invasion, pleural invasion, cancer invasive factors and mucin production.

Conclusions

CA 19-9 and CYFRA 21-1 are independent prognostic markers in patients with advanced lung adenocarcinoma. Combined use of CA 19-9 and CYFRA 21-1 provides further prognostic information in patients with advanced lung adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2897-6) contains supplementary material, which is available to authorized users.

Predicting malignant transformation of esophageal squamous cell lesions by combined biomarkers in an endoscopic screening program

AIM

To determine the association of p53, carcinoembryonic antigen (CEA) and CA19-9 protein expression with esophageal carcinogenesis.

METHODS

An iodine staining endoscopic screening program of esophageal lesions was carried out in the high-incidence area of Feicheng County, China. Seventy-seven patients with basal cell hyperplasia (BCH), 247 with low-grade dysplasia (LGD), 51 with high-grade dysplasia (HGD), 134 with invasive cancer, and 80 normal controls diagnosed by mucous membrane biopsy pathology were enrolled. Immunohistochemical detection of p53, CEA and CA19-9 proteins was performed. In the ROC curve analysis, the expression of a single biomarker and the expression of a combination of biomarkers were used to predict the risk of these four esophageal lesions.

RESULTS

The positive rates of p53 protein expression in invasive cancer, HGD, LGD, BCH and the normal control groups were 53.0%, 52.9%, 35.6%, 27.3% and 20.0%, respectively; the positive rates of CA19-9 protein expression were 44.0%, 33.3%, 16.5%, 9.2% and 6.2%, respectively; the positive rates of CEA protein expression were 74.6%, 60.8%, 23.3%, 23.7% and 16.2%, respectively. The positive rates of the combined expression of the three biomarkers were 84.3%, 76.5%, 47.6%, 42.9% and 27.5%, respectively. In the receiver operating characteristic curves of the combination of the three biomarkers, the specificity was 88.8% for the normal controls, and the sensitivity was 58.2% for invasive cancer, 25.5% for HGD, 11.2% for LGD, and 6.5% for BCH.

CONCLUSION

p53, CEA and CA19-9 protein expression was correlated with esophageal carcinogenesis, and testing for the combination of these biomarkers is useful for identifying high-risk patients with precancerous lesions.

Increased pre-surgical numbers of endothelial progenitor cells and circulating endothelial cells in colorectal cancer fail to predict outcome

INTRODUCTION

The endothelium and angiogenesis are therapeutic targets in cancer. Response to treatment may be assessed by laboratory plasma markers such as circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), von Willebrand factor (vWf), soluble E selectin, vascular endothelial growth factor (VEGF) and angiogenin. We hypothesised that these markers, obtained before surgery, would predict 2-year outcome after surgery with or without anti-angiogenic therapy for colorectal cancer (CRC).

METHODS

We recruited 154 patients with CRC, of whom 51 were treated with surgery alone, 74 were treated with standard chemotherapy (5-fluorouracil) and 29 were treated with standard chemotherapy plus anti-VEGF therapy (Avastin). Peripheral blood was taken before surgery. CD34(+)/CD45(-)/CD146(+) CECs and CD34(+)/CD45(-)/CD309 [KDR](+) EPCs were measured by flow cytometry and plasma markers by ELISA.

RESULTS

After a mean of 2.1 years follow-up (range 1.9-2.3 years), 52 of the patients (33.7 %) experienced a poor outcome (radiological and/or histological evidence of tumour spread or recurrence, or death [n = 26]). In univariate analysis, poor outcome was linked to Dukes' stage (p < 0.001), American Joint Committee on Cancer (AJCC) stage (p < 0.001), type of treatment (surgery alone, standard chemotherapy with or without anti-antigenic therapy) (p = 0.047), CECs (p < 0.02) and EPCs (p < 0.01). In subsequent binary logistic regression analysis, only Dukes' stage (hazard ratio 2.3, 95 % confidence interval 1.0-5.3, p = 0.047) and modified AJCC stage (4.62, 1.88-11.33, p < 0.001) predicted a poor outcome.

CONCLUSION

Endothelial cell markers (CECs, EPCs, vWf, soluble E selectin) and growth factors (VEGF and angiogenin), measured before surgery, have nothing extra to offer in predicting 2-year outcome in colorectal cancer when compared to Dukes' or AJCC stage.

Relationship between adhesion molecules and virological response to pegylated interferon-alpha-2a treatment in patients with chronic hepatitis B: A pilot study

AIM

We performed a clinical study to investigate potential association between serum levels of soluble adhesion molecules and virological response to pegylated interferon-alpha-2a (PEG IFN-α-2a) treatment in patients with chronic hepatitis B (CHB).

METHODS

Thirty-two patients with chronic hepatitis B virus genotype B were recruited in this study, who were treated with PEG IFN-α-2a 180 μg every week and then followed up for 24 weeks. Thirty healthy control subjects were recruited from volunteer blood donors. Serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin (sE-selectin), soluble L-selectin (sL-selectin) in patients were investigated by enzyme-linked immunoassay before and after treatment.

RESULTS

Serum concentrations of sICAM-1, sVCAM-1, sE-selectin and sL-selectin in CHB patients were significantly higher compared to the control group before treatment (P < 0.00001, respectively). In CHB patients responding to the PEG IFN-α-2a treatment, serum levels of sICAM-1, sVCAM-1, sE-selectin and sL-selectin were higher than those in non-responders before treatment (PI  = 0.001, PV  = 0.002, PE  = 0.02, PL  = 0.004). The levels of sICAM-1, sVCAM-1, sE-selectin and sL-selectin decreased in virological responders of treatment at 12 and 24 weeks (PI  = 0.0001, PV  = 0.00004, PE  = 0.002, PL  = 0.0004; PI  = 0.00007, PV  = 0.00001, PE  = 0.0003, PL  = 0.00003), while no obvious changes were observed in non-responders (P > 0.05, respectively).

CONCLUSION

Results obtained indicated increased levels of sICAM-1, sVCAM-1, sE-selectin and sL-selectin could be related to virological response to PEG IFN-α-2a treatment in CHB patients, and have a prognostic effect on virological response.

Effect of standard chemotherapy and antiangiogenic therapy on plasma markers and endothelial cells in colorectal cancer

Introduction:

The importance of the endothelium in angiogenesis and cancer is undisputed, and its integrity may be assessed by laboratory markers such as circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), plasma von Willebrand factor (vWf), soluble E selectin, vascular endothelial growth factor (VEGF) and angiogenin. Antiantigenic therapy may be added to standard cytotoxic chemotherapy as a new treatment modality. We hypothesised that additional antiangiogenic therapy acts in a contrasting manner to that of standard chemotherapy on the laboratory markers.

Methods:

We recruited 68 patients with CRC, of whom 16 were treated with surgery alone, 32 were treated with surgery followed by standard chemotherapy (5-flurouracil), and 20 were treated with surgery followed by standard chemotherapy plus anti-VEGF therapy (Avastin). Peripheral blood was taken before surgery, and again 3 months and 6 months later. CD34⁺/CD45⁻/CD146⁺ CECs and CD34⁺/CD45⁻/CD309[KDR]⁺ EPCs were measured by flow cytometry, plasma markers by ELISA.

Results:

In each of the three groups, CECs and EPCs fell at 3 months but were back at pre-surgery levels at 6 months (P<0.05). VEGF was lower in both 3-and 6-month samples in the surgery-only and surgery plus standard chemotherapy groups (P<0.05), but in those on surgery followed by standard chemotherapy plus anti-VEGF therapy, low levels at 3 months (P<0.01) increased to pre-surgery levels at 6 months. In those having surgery and standard chemotherapy, soluble E selectin was lower, whereas angiogenin was higher at 6 months than at baseline (both P<0.05).

Conclusions:

We found disturbances in endotheliod cells regardless of treatment, whereas VEGF returned to levels before surgery in those on antiangiogenic therapy. These observations may have clinical and pathophysiological implications.

Serum carbohydrate antigen 19-9 as an indicator of liver metastasis in colorectal carcinoma cases

PURPOSE

The liver is the organ to which colorectal carcinomas (CRCs) most commonly metastasize, and surgical resection has been established as the most effective and potentially curative treatment for CRC with liver metastasis (LM). Therefore, surveillance of LM is vital for improvement of prognosis of CRC patients. In this study, we aimed to explore the potential value of carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA), and marker enzymes in indicating LM with CRC.

METHODS

Three groups of eligible patients with metastatic cancers were retrospectively included: CRC patients with LM (CRC-LM) or without LM (CRC- NLM), and non-CRC patients with LM (NCRC-LM). All metastatic lesions were identified by CT or MRI. Data on characteristics of the patients, the primary site, the locations of metastasis, CA 19-9, CEA, and biochemical parameters were collected for analysis.

RESULTS

A total of 493 patients were retrospectively included. More alcohol consumption was found in CRC-LM than CRC-NLM. Some biochemical enzymes were found to be significantly higher in groups with LM than without (CRC-LM or NCRC-LM v.s CRC-NLM). Both CEA and CA 19-9 were much higher in CRC-LM than CRC-NLM or NCRC-LM. For CRC patients, CA 19-9, γ-glutamyl transpeptidase, CEA and alcohol consumption were identified as independent factors associated with LM.

CONCLUSION

Our analysis suggested the CA 19-9 might be a potential valuable indicator for LM of CRC in the clinic.

Efficacy of ex vivo activated and expanded natural killer cells and T lymphocytes for colorectal cancer patients

Immune cell-based therapies using natural killer (NK) cells and cytotoxic T cells are under constant scrutiny, with the aim to design an effective and reduced-toxicity therapy, which will benefit patients via improved quality of life and improved prognosis. Four patients with stage IV colon cancer were administered 1, 3, 5 and 6 effector cell intravenous infusions, respectively. Peripheral blood was collected from the patients and the ex vivo activation and expansion of NK and T cells was performed in Good Manufacturing Practice-certified clean rooms for ~12-15 days. Immunophenotypic analysis of the peripheral blood mononuclear cells (PBMCs) and expanded NK and T cells was conducted using flow cytometry and the patients were followed up. On average, 4.8×10⁷ initial PBMCs and 2.7×10⁹ total expanded cells were obtained. The intravenous infusions of the expanded cells were not accompanied by adverse reactions. Improved prognosis, reflected by a considerable decrease in the cancer markers, accompanied by an improved quality of life in the patients were observed. In conclusion, potential strategies are currently under development for the large-scale production of effectors cells; therefore, autologous immune enhancement therapy (AIET) may be considered as a viable approach to cancer treatment.

Research and clinical applications of molecular biomarkers in gastrointestinal carcinoma (Review)

Gastrointestinal (GI) carcinoma is a common malignant disease worldwide. Its development and progression is a multistage process involving a multifactorial etiology. Although the detailed mechanisms of the development of GI carcinoma remain controversial, the elucidation of its molecular biology over the last few years has resulted in a better perspective on its epidemiology, carcinogenesis and pathogenesis. More significantly, it is currently possible to use biological indicators or biomarkers in differential diagnosis, prognostic evaluation and specific clinical interventions. In this review, we aimed to describe the biomarkers of pathogenesis, invasion, metastasis and prognosis of GI carcinoma and discuss their potential clinical applications. The majority of these biomarkers, such as tumor-associated antigens, oncogenes and tumor suppressor genes, metastasis-associated genes, cell adhesion molecules, cytokines, growth factors and microRNAs, are currently broadly applicable.

Biomarkers for predicting future metastasis of human gastrointestinal tumors

The recent advances in surgery and radiation therapy have significantly improved the prognosis of patients with primary cancer, and the major challenge of cancer treatment now is metastatic disease development. The 5-year survival rate of cancer patients who have distant metastasis at diagnosis is extremely low, suggesting that prediction and early detection of metastasis would definitely improve their prognosis because suitable patient therapeutic management and treatment strategy can be provided. Cancer cells from a primary site give rise to a metastatic tumor via a number of steps which require the involvement and altered expression of many regulators. These regulators may serve as biomarkers for predicting metastasis. Over the past few years, numerous regulators have been found correlating with metastasis. In this review, we summarize the findings of a number of potential biomarkers that are involved in cadherin-catenin interaction, integrin signaling, PI3K/Akt/mTOR signaling and cancer stem cell identification in gastrointestinal cancers. We will also discuss how certain biomarkers are associated with the tumor microenvironment that favors cancer metastasis.

Angiogenin outperforms VEGF, EPCs and CECs in predicting Dukes' and AJCC stage in colorectal cancer

BACKGROUND

Circulating endothelial cells (CECs), endothelial progenitor cells (EPCs), Willebrand factor (vWf), soluble E-selectin, vascular endothelial growth factor (VEGF) and angiogenin are of interest in cancer vascular biology. However, few studies have looked at more than one in combination. We set out to determine which would be best in predicting the Dukes' and American Joint Committee on Cancer (AJCC) scores in colorectal cancer patients.

METHODS

We recruited 154 patients with colorectal cancer, 29 healthy controls and 26 patients with benign bowel disease. CD34(+) /CD45(-) /CD146(+) CECs and CD34(+) /CD45(-) /CD309[KDR](+) EPCs were measured by flow cytometry, plasma markers by ELISA.

RESULTS

All research indices were raised in colorectal cancer (P < 0·05) compared to control groups. Although CECs (P < 0·05), EPCs (P < 0·01) and angiogenin (P < 0·01) increased stepwise across the four Dukes' stages and four AJCC stages, only angiogenin remained significant in multiple regression analysis (P = 0·003 for Dukes, P = 0·01 for AJCC). Angiogenin levels were higher in Dukes' stages C and D compared to stage A, and AJCC stages 4-6 and 7-10 compared to stage 1 (all P < 0·05). Adding a second research marker to angiogenin did not markedly improve this relationship.

CONCLUSION

Although we found disturbances in endotheliod cells and plasma markers of the endothelium and growth factors, only angiogenin levels were independently associated with progression of the Dukes' stage and AJCC stage, with the association with Duke's stage being stronger. We suggest that angiogenin is a potential biomarker in risk stratification for colorectal cancer, and may aid clinical decision making.

Prognostic value of tumor growth factor levels during chemotherapy in patients with metastatic colorectal cancer

Tumor growth and angiogenic factors are usually overexpressed in colorectal carcinomas. We aimed to assess the prognostic role of VEGF, bFGF, PDGF-AA, EGF, HGF, and E-selectin in patients with metastatic colorectal cancer treated with capecitabine and oxaliplatin (XELOX) chemotherapy protocol. Thirty-eight colorectal cancer patients who had evidence of distant metastasis were enrolled in the study. Angiogenic factors were measured before and after third cycle of chemotherapy. Patients were randomized into three groups, partial response (PR), stable disease (SD), and progressive disease (PD) groups, according to their clinical and radiologic evaluation after three cycles of XELOX chemotherapy. Eighteen patients (47.3 %) achieved partial response, 10 (26.3 %) stable disease, and 10 (26.3 %) progressive disease. VEGF (63.20 Pg/ml vs. 19,79 Pg/ml; p < 0.001), EGF (7.29 ± 3.08 Pg/ml vs. 4.79 ± 2.05 Pg/ml; p < 0.011), HGF (618.16 ± 340.39 Pg/ml vs. 452.02 ± 217.18 Pg/ml; p < 0.049), and PDGF-AA (691.68 ± 187.10 Pg/ml vs. 404.89 ± 168.47 Pg/ml; p < 0.001) were significantly decreased in PR group. PDGF-AA levels were also decreased in SD group (706.66 ± 206.66 Pg/ml vs. 389.79 ± 143.16 Pg/ml; p < 0,001). HGF levels were significantly increased in PD disease group (449.99 Pg/ml vs. 682.22 Pg/ml; p < 0.046). The baseline E-selectin levels were inversely proportional with overall survival that could be an important prognostic factor at the time of diagnosis. This study demonstrated that tumor growth factors can be helpful to determine colorectal cancer prognosis and overall survival in patients with metastatic disease. VEGF, HGF, EGF, and PDGF-AA levels were decreased in PR group. However, meaningful increment was seen HGF levels in PD group. Angiogenic factors and E-selectin provided unique prognostic information in advanced colorectal carcinoma patients.

Selectins and Associated Adhesion Proteins in Inflammatory disorders

Inflammation is defined as the normal response of living tissue to injury or infection. It is important to emphasize two components of this definition. First, that inflammation is a normal response and, as such, is expected to occur when tissue is damaged. Infact, if injured tissue does not exhibit signs of inflammation this would be considered abnormal and wounds and infections would never heal without inflammation. Secondly, inflammation occurs in living tissue, hence there is need for an adequate blood supply to the tissues in order to exhibit an inflammatory response. The inflammatory response may be triggered by mechanical injury, chemical toxins, and invasion by microorganisms, and hypersensitivity reactions. Three major events occur during the inflammatory response: the blood supply to the affected area is increased substantially, capillary permeability is increased, and leucocytes migrate from the capillary vessels into the surrounding interstitial spaces to the site of inflammation or injury. The inflammatory response represents a complex biological and biochemical process involving cells of the immune system and a plethora of biological mediators. Cell-to-cell communication molecules such as cytokines play an extremely important role in mediating the process of inflammation. Inflammation and platelet activation are critical phenomena in the setting of acute coronary syndromes. An extensive exposition of this complex phenomenon is beyond the scope of this article (Rankin 2004).

Enhancing the therapeutic efficacy of adenovirus in combination with biomaterials

With the reason that systemically administered adenovirus (Ad) is rapidly extinguished by innate/adaptive immune responses and accumulation in liver, in vivo application of the Ad vector is strictly restricted. For achieving to develop successful Ad vector systems for cancer therapy, the chemical or physical modification of Ad vectors with polymers has been generally used as a promising strategy to overcome the obstacles. With polyethylene glycol (PEG) first in order, a variety of polymers have been developed to shield the surface of therapeutic Ad vectors and well accomplished to extend circulation time in blood and reduce liver toxicity. However, although polymer-coated Ads can successfully evacuate from a series of guarding systems in vivo and locate within tumors by enhanced permeability and retention (EPR) effect, the possibility to entering into the target cell is few and far between. To endow targeting moiety to polymer-coated Ad vectors, a diversity of ligands such as tumor-homing peptides, growth factors or antibodies, have been introduced with avoiding unwanted transduction and enhancing therapeutic efficacy. Here, we will describe and classify the characteristics of the published polymers with respect to Ad vectors. Furthermore, we will also compare the properties of variable targeting ligands, which are being utilized for addressing polymer-coated Ad vectors actively.