A Review of the Current Status and Concept of the Emerging Implications of Zinc and Zinc Transporters in the Development of Pancreatic Cancer

Construction of a prognostic model for colorectal adenocarcinoma based on Zn transport-related genes identified by single-cell sequencing and weighted co-expression network analysis

Background

Colorectal cancer (CRC) is one of the most prevalent malignancies and the third most lethal cancer globally. The most reported histological subtype of CRC is colon adenocarcinoma (COAD). The zinc transport pathway is critically involved in various tumors, and its anti-tumor effect may be through improving immune function. However, the Zn transport pathway in COAD has not been reported.

Methods

The determination of Zn transport-related genes in COAD was carried out through single-cell analysis of the GSE 161277 obtained from the GEO dataset. Subsequently, a weighted co-expression network analysis of the TCGA cohort was performed. Then, the prognostic model was conducted utilizing univariate Cox regression and least absolute shrinkage and selection operator (LASSO) Cox regression analysis. Functional enrichment, immune microenvironment, and survival analyses were also carried out. Consensus clustering analysis was utilized to verify the validity of the prognostic model and explore the immune microenvironment. Ultimately, cell experiments, including CCK-8,transwell and scratch assays, were performed to identify the function of LRRC59 in COAD.

Results

According to the Zn transport-related prognostic model, the individuals with COAD in TCGA and GEO databases were classified into high- and low-risk groups. The group with low risk had a comparatively more favorable prognosis. Two groups had significant variations in the immune infiltration, MHC, and the expression of genes related to the immune checkpoint. The cell experiments indicated that the proliferation, migration, and invasion of the HCT-116, DLD-1, and RKO cell lines were considerably increased after LRRC59 knockdown. It proved that LRRC59 was indeed a protective factor for COAD.

Conclusion

A prognostic model for COAD was developed using zinc transport-related genes. This model can efficiently assess the immune microenvironment and prognosis of individuals with COAD. Subsequently, the function of LRRC59 in COAD was validated via cell experiments, highlighting its potential as a biomarker.

Using micro-synchrotron radiation x-ray fluorescence (µ-SRXRF) for trace metal imaging in the development of MRI contrast agents for prostate cancer imaging

BACKGROUND

Contrast agents (CA) are administered in magnetic resonance imaging (MRI) clinical exams to measure tissue perfusion, enhance image contrast between adjacent tissues, or provide additional biochemical information in molecular MRI. The efficacy of a CA is determined by the tissue distribution of the agent and its concentration in the extracellular space of all tissues.

METHODS

In this work, micro-synchrotron radiation x-ray fluorescence (µ-SRXRF) was used to examine and characterize a gadolinium-based zinc-sensitive agent (GdL2) currently under development for detection of prostate cancer (PCa) by MRI. Prostate tissue samples were collected from control mice and mice with known PCa after an MRI exam that included injection of GdL2. The samples were raster scanned to investigate trends in Zn, Gd, Cu, Fe, S, P, and Ca.

RESULTS

Significant Zn and Gd co-localization was observed in both healthy and malignant tissues. In addition, a marked decrease in Zn was found in the lateral lobe of the prostate obtained from mice with PCa.

CONCLUSION

We demonstrate here that µ-SRXRF is a useful tool for monitoring the distribution of several elements including Zn and Gd in animal models of cancer. The optimized procedures for tissue preparation, processing, data collection, and analysis are described.

Multistage Photoactivatable Zinc-Responsive Nanodevices for Monitoring and Regulating Dysfunctional Islet β-Cells

The dysfunctional islet β-cell triggered by excessive deposition of Zn²⁺ constituted a striking indicator of the occurrence of diabetic disease. However, it remained a formidable challenge to reflect the real-time function of β-cell by monitoring the Zn²⁺ content. Herein, multistage photoactivatable Zn²⁺-responsive nanodevice (denoted as AD2@USD1) was presented for sensing, regulating, and evaluating Zn²⁺ levels in dysfunctional islet β-cells. The photoactivated signatures on the satellite shell layer of the nanodevices and the internally loaded chelating factors effectively identified and intervened in the real-time concentration of Zn²⁺, the photothermal feedback component decorated on the inner core permitted the assessment of the post-intervention Zn²⁺ levels, achieving an integrated intervention and prognostic assessment in response to the abnormal islet β-cell function induced by Zn²⁺ deposition. In this way, one strategy for sensing and regulating islet β-cell function-oriented to Zn²⁺ was established. Our study introduced AD2@USD1 as a tool for effectively sensing, adjusting, and assessing the Zn²⁺ level in islet β-cells with abnormalities, gaining a potential breakthrough in the treatment of diabetes.

Design of 99mTc-labeled zinc-chelating imaging probe for SPECT imaging of the pancreas

Early and sensitive diagnosis of pancreatic diseases is a contemporary clinical challenge. Zinc level in pancreatic tissue and its secretion in pancreatic juice has long been considered a surrogate marker of pancreatic function. The objective of this study was to design a Zn-chelating imaging probe (ZCIP) which could be labeled with ^99mTc radionuclide for imaging of pancreas using single photon emission tomography (SPECT). We synthesized ZCIP as a bifunctional chelate consisting of diethylene triamine pentaacetic acid for ^99mTc-chelation at one end and bispicolylethylamine for Zn-complexation at the other end. ZCIP was labeled with ^99mTc by standard Sn²⁺-based reduction method. The ^99mTc-labeled ZCIP was studied in normal mice (0.3 mCi) for SPECT imaging. We found that ZCIP consistently labeled with ^99mTc radionuclide with over 95% efficiency. Addition of ZCIP altered the spectrum of standard dithizone-Zn complex, indicating its ability to chelate Zn. SPECT data demonstrated the ability of ^99mTc-ZCIP to image pancreas with high sensitivity in a non-invasive manner; liver and spleen were the other major organs of ^99mTc-ZCIP uptake. Based on these results, we conclude that ^99mTc-ZCIP presents as a novel radiotracer for pancreas imaging for diagnosis of diseases such as pancreatitis.

Cytotoxicity, oxidative stress, and apoptosis in human embryonic kidney (HEK293) and colon cancer (SW480) cell lines exposed to nanoscale zeolitic imidazolate framework 8 (ZIF-8)

Zinc (zeolitic) imidazolate framework 8 (ZIF-8) has been widely considered in the literature as an ideal candidate for drug delivery especially anti-cancer drugs. However, the available information on the biocompatibility and cytotoxicity of ZIF-8 nanoparticles is contradictory. Therefore, in the present study, the ZIF-8 particles were synthetized, characterized, and their potential toxicity on two eukaryotic cell lines including human embryonic kidney (HEK293) and human colon cancer (SW480) cells was investigated in vitro. The characterization of ZIF-8 particles by TEM, EDX, SEM, and DLS indicated the synthesis of the hexagonal crystals with mean diameter of 124.71±32.74 nm and the presence of the zinc element at 86.25% by weight (wt%) of the ZIF-8 structure. The results of the cytotoxicity assessment of ZIF-8 NPs showed that the viability of two different cell lines reduced significantly coincident with increasing exposure concentration from 0 to 500 μg mL^-1 (P<0.05). The 24-h half-inhibitory concentration (IC50-24 h) values of ZIF-8 NPs for HEK293 and SW480 cell lines were 116.22 and 36.23 μg mL^-1, respectively. We found that the viability of SW480 cells was significantly lower than the HEK293 cells in all exposure concentrations of ZIF-8 NPs except control. Exposure of both cells resulted in increasing of the intracellular reactive oxygen species (ROS) production and activation of apoptosis pathway. The apoptosis rate of cancer SW480 cells was higher than the normal HEK293 cells. These findings indicate that synthetized ZIF-8 NPs could be a candidate for cancer therapy, although their toxic effects on the normal cells also should be considered.

Survival of Laryngeal Cancer Patients Depending on Zinc Serum Level and Oxidative Stress Genotypes

Stress contributes to various aspects of malignancy and could influence survival in laryngeal cancer patients. Among antioxidant mechanisms, zinc and the antioxidant enzymes superoxide dismutase 2, catalase and glutathione peroxidase 1 play a major role. The aim of this study was a prospective evaluation of the survival of patients with laryngeal cancer in relation to serum levels of zinc in combination with functional genotype differences of three key antioxidant enzymes. The study group consisted of 300 patients treated surgically for laryngeal cancer. Serum zinc levels and common polymorphisms in SOD2, CAT and GPX1 were analyzed. The risk of death in patients with the lowest zinc levels was increased in comparison with patients with the highest levels. Polymorphisms of antioxidant genes by themselves were not correlated with survival, however, serum zinc level impact on survival was stronger for SOD2 TC/TT and CAT CC variants. GPX1 polymorphisms did not correlate with zinc levels regarding survival. In conclusion, serum zinc concentration appears to be an important prognostic factor for survival of patients diagnosed with laryngeal cancer. When higher zinc levels were correlated with polymorphisms in SOD2 and CAT a further increase in survival was observed.

Increased expression of zinc transporter ZIP4, ZIP11, ZnT1, and ZnT6 predicts poor prognosis in pancreatic cancer

INTRODUCTION

Zinc homeostasis is regulated by SLC39A/ZIP, SLC30A/ZnT, and metallothionein (MT) families in human cells. Zinc dyshomeostasis may affect or be affected by the abnormal behavior of cancer cells. Although decreased serum zinc levels are observed in patients with pancreatic adenocarcinoma (PAAD), limited information is available regarding the expression pattern and prognostic roles of zinc homeostasis-related genes in PAAD.

OBJECTIVES

The primary objective of this study was to explore the expression pattern and prognostic roles of zinc homeostasis-related genes in PAAD.

METHODS

The expression pattern of 35 known zinc homeostasis-related genes in PAAD was systemically explored based on RNA-sequencing data from the Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) projects. The association between the expression levels of zinc homeostasis-related genes and survival of PAAD patients was evaluated using the Kaplan-Meier method and the log-rank test. Expressional correlation between zinc homeostasis-related genes with potential prognostic value in PAAD and normal pancreatic controls was evaluated using Pearson's correlation analysis. Functional enrichment analyses were performed to elucidate possible mechanisms for the potential prognostic and therapeutic roles of these zinc homeostasis-related genes in PAAD. Effects of ZIP11, ZnT1, or ZnT6 knockdown on the proliferation and the migration of Capan-1 pancreatic cancer cells were assessed by the CCK-8 assay and the wound healing assay respectively.

RESULTS

We demonstrated that the expression levels of ZIP1, ZIP3, ZIP4, ZIP6, ZIP7, ZIP9, ZIP10, ZIP11, ZIP13, ZnT1, ZnT5, ZnT6, ZnT7, and ZnT9 were increased, whereas the expression levels of ZIP5, ZIP14, ZnT2, MT1 G, MT1H, and MT1X were decreased in PAAD tumors compared with normal pancreatic controls. Among these differentially-expressed genes related to zinc homeostasis, higher expression of ZIP4, ZIP11, ZnT1 or ZnT6 predicted poorer prognosis with the possible involvement of several cancer-related processes and pathways in PAAD patients. We further demonstrated that knockdown of ZIP11 attenuated Capan-1 cell proliferation with decreased activation of ERK1/2 pathway; knockdown of ZnT1 attenuated Capan-1 cell proliferation with decreased activation of ERK1/2, p38 MAPK, NF-kB, and mTOR pathways; knockdown of ZnT6 attenuated Capan-1 cell proliferation with decreased activation of ERK1/2, p38 MAPK, and NF-kB pathways.

CONCLUSIONS

Higher expression of the zinc transporter ZIP4, ZIP11, ZnT1 or ZnT6 predicted poorer prognosis in patients with PAAD. These findings provide new clues for understanding the complex relationship between zinc homeostasis and pancreatic cancer.

Zinc: The Wonder Drug for the Treatment of Carcinomas

Evidence is evolving that support the relationship that all carcinomas exhibit the following important relationships: The malignant cells exhibit a significant decreased zinc compared to the normal cells. The higher zinc levels that exist in the normal cells are cytotoxic in the malignant cells. The decrease in zinc is due to the down regulation of the ZIP-family zinc uptake transporter. These cells are as "ZIP-deficient/decreased zinc" malignancies. This provides a target for a chemotherapy that can restore the high zinc levels that will manifest cytotoxic effects in the malignant cells. In order to achieve this, a vehicle that facilitates the uptake and accumulation of zinc in the ZIP-deficient cells is required. The zinc ionophore, clioquinol, exhibits the properties that will provide these requirements. This is demonstrated by the treatment of a patient with 3% Clioquinol Cream, which successfully suppressed the progression of androgen-dependent prostate cancer. This treatment should also be efficacious for pancreatic cancer, liver cancer, breast cancer, thyroid cancer, kidney cancer, stomach cancer, gall bladder cancer, and lung cancer; which are carcinomas that exhibit decreased zinc. Thus, it is appropriate to describe that "Zinc is the wonder drug for the treatment of carcinomas".

Zinc dysregulation in cancers and its potential as a therapeutic target

Zinc is an essential element and serves as a structural or catalytic component in many proteins. Two families of transporters are involved in maintaining cellular zinc homeostasis: the ZIP (SLC39A) family that facilitates zinc influx into the cytoplasm, and the ZnT (SLC30A) family that facilitates zinc efflux from the cytoplasm. Zinc dyshomeostasis caused by the dysfunction of zinc transporters can contribute to the initiation or progression of various cancers, including prostate cancer, breast cancer, and pancreatic cancer. In addition, intracellular zinc fluctuations lead to the disturbance of certain signaling pathways involved in the malignant properties of cancer cells. This review briefly summarizes our current understanding of zinc dyshomeostasis in cancer, and discusses the potential roles of zinc or zinc transporters in cancer therapy.

Synchrotron Radiation X-ray Fluorescence Elemental Mapping in Healthy versus Malignant Prostate Tissues Provides New Insights into the Glucose-Stimulated Zinc Trafficking in the Prostate As Discovered by MRI

Prostatic zinc content is a known biomarker for discriminating normal healthy tissue from benign prostatic hyperplasia (BPH) and prostate cancer (PCa). Given that zinc content is not readily measured without a tissue biopsy, we have been exploring noninvasive imaging methods to detect these diagnostic differences using a zinc-responsive MRI contrast agent. During imaging studies in mice, we observed that a bolus of glucose stimulates secretion of zinc from the prostate of fasted mice. This discovery allowed the use of a Gd-based zinc sensor to detect differential zinc secretion in regions of healthy versus malignant prostate tissue in a transgenic adenocarcinoma mouse model of PCa. Here, we used a zinc-responsive MRI agent to detect zinc release across the prostate during development of malignancy and confirm the loss of total tissue zinc by synchrotron radiation X-ray fluorescence (μSR-XRF). Quantitative μSR-XRF results show that the lateral lobe of the mouse prostate uniquely accumulates high concentrations of zinc, 1.06 ± 0.08 mM, and that the known loss of zinc content in the prostate is only observed in the lateral lobe during development of PCa. Additionally, we confirm that lesions identified by a loss of zinc secretion indeed represent malignant neoplasia and that the relative zinc concentration in the lesion is reduced to 0.370 ± 0.001 mM. The μSR-XRF data also provided insights into the mechanism of zinc secretion by showing that glucose promotes movement of zinc pools (∼1 mM) from the glandular lumen of the lateral lobe of the mouse prostate into the stromal/smooth muscle surrounding the glands. Co-localization of zinc and gadolinium in the stromal/smooth muscle areas as detected by μSR-XRF confirm that glucose initiates secretion of zinc from intracellular compartments into the extracellular spaces of the gland where it binds to the Gd-based agent and albumin promoting MR image enhancement.

New Insight into Polydopamine@ZIF-8 Nanohybrids: A Zinc-Releasing Container for Potential Anticancer Activity

Despite the initial evidence on the role of zinc and zinc transporters in cancer prevention, little attention has been paid to the zinc-derived compounds. In the present work, we reported a strategy to prepare a kind of zinc-releasing container with enhanced biocompatibility and release dynamics using ZIF-8 nanocrystals as the sacrificial templates. Transmission electron microscopy (TEM) analysis demonstrated that the ZIF-8 nanocrystals were gradually etched out in the aqueous media within 48 h, resulting in hollow nanocapsules. Notably, we found the self-polymerization of dopamine can form nanoshells around the ZIF-8 nanocrystals, which served as a type of functional membranes during the release of zinc. More interestingly, PDA@ZIF-8⁻based nanohybrids expressed stronger inhibition to the cancer cell growth, which implied that the nanohybrids could be a drug carrier for chemotherapy. This study broadens the biomedical application of ZIF-8 and also provides a versatile strategy toward the development of multifunctional delivery system.

The association between dietary zinc intake and risk of pancreatic cancer: a meta-analysis

Previous reports have suggested a potential association on dietary zinc intake with the risk of pancreatic cancer. Since the associations between different studies were controversial, we therefore conducted a meta-analysis to reassess the relationship between dietary zinc intake and pancreatic cancer risk. A comprehensive search from the databases of PubMed, Embase, Web of Science, and Medline was performed until January 31, 2017. Relative risk (RR) with 95% confidence intervals (CI) derived by using random effect model was used. Sensitivity analysis and publication bias were conducted. Our meta-analysis was based on seven studies involving 1659 cases, including two prospective cohort studies and five case–control studies. The total RR of pancreatic cancer risk for the highest versus the lowest categories of dietary zinc intake was 0.798 (0.621–0.984), with its significant heterogeneity among studies (I²=58.2%, P=0.026). The average Newcastle–Ottawa scale (NOS) score was 7.29, suggesting a high quality. There was no publication bias in the meta-analysis about dietary zinc intake on the risk of pancreatic cancer. Subgroup analyses showed that dietary zinc intake could reduce the risk of pancreatic cancer in case–control studies and among American populations. In conclusion, we found that highest category of dietary zinc intake can significantly reduce the risk of pancreatic cancer, especially among American populations.

New developments in the early diagnosis of pancreatic cancer

Pancreatic cancer is an aggressive carcinoma of the digestive system and radical resection, which is available to very few patients, is the only possibility for cure. Since therapeutic choices are limited at the advanced stage, screening and early diagnostic tools are indispensable for a better prognosis. Areas covered: This review illustrates serologic and imaging examinations, and carbohydrate antigens, microRNAs, methylation biomarkers, molecules in exosomes, ultrasound, computed tomography, magnetic resonance imaging, positron emission tomography and endoscopic retrograde cholangiopancreatography, among other topics. No matter which approach is used, the accuracy of early diagnosis is extremely low. Combining different methods greatly improves the accuracy of early diagnosis. This review was conducted utilizing PubMed with key search words pancreatic cancer, early diagnosis, biomarkers and imaging. Expert commentary: Appropriate combination of biomarkers and imaging technologies will become standard practice in the future. Because the incidence of and mortality from pancreatic cancer is rising, further study of new approaches for the early detection of pancreatic tumors is essential.

Zinc transporters and dysregulated channels in cancers

As a nutritionally essential metal ion, zinc (Zn) not only constitutes a structural element for more than 3000 proteins but also plays important regulatory functions in cellular signal transduction. Zn homeostasis is tightly controlled by regulating the flux of Zn across cell membranes through specific transporters, i.e. ZnT and ZIP family proteins. Zn deficiency and malfunction of Zn transporters have been associated with many chronic diseases including cancer. However, the mechanisms underlying Zn regulatory functions in cellular signaling and their impact on the pathogenesis and progression of cancers remain largely unknown. In addition to these acknowledged multifunctions, Zn modulates a wide range of ion channels that in turn may also play an important role in cancer biology. The goal of this review is to propose how zinc deficiency, through modified Zn homeostasis, transporter activity and the putative regulatory function of Zn can influence ion channel activity, and thereby contribute to carcinogenesis and tumorigenesis. This review intends to stimulate interest in, and support for research into the understanding of Zn-modulated channels in cancers, and to search for novel biomarkers facilitating effective clinical stratification of high risk cancer patients as well as improved prevention and therapy in this emerging field.

Decreased zinc in the development and progression of malignancy: an important common relationship and potential for prevention and treatment of carcinomas

INTRODUCTION

Efficacious chemotherapy does not exist for treatment or prevention of prostate, liver, and pancreatic carcinomas, and some other cancers that exhibit decreased zinc in malignancy. Zinc treatment offers a potential solution; but its support has been deterred by adverse bias. Areas covered: 1. The clinical and experimental evidence for the common ZIP transporter/Zn down regulation in these cancers. 2. The evidence for a zinc approach to prevent and/or treat these carcinomas. 3. The issues that introduce bias against support for the zinc approach. Expert opinion: ZIP/Zn downregulation is a clinically established common event in prostate, hepatocellular and pancreatic cancers. 2. Compelling evidence supports the plausibility that a zinc treatment regimen will prevent development of malignancy and termination of progressing malignancy in these cancers; and likely other carcinomas that exhibit decreased zinc. 3. Scientifically-unfounded issues that oppose this ZIP/Zn relationship have introduced bias against support for research and funding of a zinc treatment approach. 4. The clinically-established and supporting experimental evidence provide the scientific credibility that should dictate the support for research and funding of a zinc approach for the treatment and possible prevention of these cancers. 5. This is in the best interest of the medical community and the public-at-large.

Cellular sensing and transport of metal ions: implications in micronutrient homeostasis

Micronutrients include the transition metal ions zinc, copper and iron. These metals are essential for life as they serve as cofactors for many different proteins. On the other hand, they can also be toxic to cell growth when in excess. As a consequence, all organisms require mechanisms to tightly regulate the levels of these metal ions. In eukaryotes, one of the primary ways in which metal levels are regulated is through changes in expression of genes required for metal uptake, compartmentalization, storage and export. By tightly regulating the expression of these genes, each organism is able to balance metal levels despite fluctuations in the diet or extracellular environment. The goal of this review is to provide an overview of how gene expression can be controlled at a transcriptional, posttranscriptional and posttranslational level in response to metal ions in lower and higher eukaryotes. Specifically, I review what is known about how these metalloregulatory factors sense fluctuations in metal ion levels and how changes in gene expression maintain nutrient homeostasis.

The cytotoxic role of RREB1, ZIP3 zinc transporter, and zinc in human pancreatic adenocarcinoma

Pancreatic cancer (ductal adenocarcinoma) remains a deadly cancer with ~85% mortality, and a 5-year survival rate of ~6% or less for the past 30 years. The factors and events associated with the development of pancreatic cancer are poorly identified. As such, effective biomarkers for early detection of malignancy are lacking. Efficacious chemotherapy once the cancer is identified does not exist. Recent clinical studies have revealed that the zinc levels are consistently and markedly decreased in adenocarcinoma as compared with normal/benign pancreatic tissue. The decreased zinc is exhibited in well-differentiated malignancy and in progressing malignancy, and also exists throughout the development of PanIN. Concurrent with the decrease in zinc, RREB1 transcription factor and ZIP3 zinc uptake transporter are downregulated. Thus, a RREB1/ZIP3/Zinc transformation appears to be an early event in the development of pancreatic cancer. We propose that this transformation is necessary to prevent the accumulation of high cellular zinc levels, which result in cytotoxic effects on the developing malignant cells. This report now demonstrates that exposure of Panc1 cells to physiological concentrations of zinc that result in increased zinc uptake and accumulation also inhibits cell proliferation. The study further shows that ZIP3 is the important transporter required for the accumulation of zinc and its inhibition of proliferation. RREB1 is identified as the positive regulator of ZIP3 expression. Therefore, the pathway of RREB1/ZIP3/Zinc and its downregulation during oncogenesis exist to prevent the accumulation of cytotoxic levels of zinc during the development and progression of the malignant cells in pancreatic adenocarcinoma.

Targeting insulin-like growth factor 1 receptor inhibits pancreatic cancer growth and metastasis

Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor β. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer.