The challenge of pancreatic cancer

Diagnostic Value of CA 19-9 and Carcinoembryonic Antigen for Pancreatic Cancer: A Meta-Analysis

Background

CA 19-9 and carcinoembryonic antigen (CEA) are widely used for the diagnosis of pancreatic cancer. The purpose of the present study was to compare the diagnostic value of CA 19-9 with CEA for pancreatic cancer.

Methods

The studies were obtained from electronic searches conducted in PubMed, Embase, and Cochrane Library databases until December 2017. The keywords included diagnosis of pancreatic cancer, CA 19-9, and CEA. The ratio of sensitivity, the specificity, the diagnostic odds ratio (DOR), and the summary of the receiver operating characteristic (SROC) with regard to CA 19-9 and CEA were measured using the random effects model. The current study included 13 studies that comprised 4,537 participants and 1,277 patients with pancreatic cancer.

Results

The levels of CA 19-9 for use for the detection of pancreatic cancer were associated with higher sensitivity (ratio of sensitivity: 1.54; 1.31–1.81; P < 0.001), DOR (DOR: 3.50; 95% CI: 2.24–5.45; P < 0.001), and AUC (ratio of AUC: 1.24; 95% CI: 1.15–1.33; P < 0.001) compared with the variable CEA, while no significant difference between CA 19-9 and CEA was noted with regard to specificity (ratio of specificity: 0.97; 95% CI: 0.89–1.06; P = 0.517). The findings of the subgroup analyses suggested that different cutoff values of CA 19-9 and CEA might affect the diagnostic value.

Conclusions

The findings of the present study indicated that CA 19-9 levels were associated with higher sensitivity, DOR, and AUC compared with the corresponding levels of CEA with regard to the diagnosis of pancreatic cancer.

Knockdown of ZFR suppresses cell proliferation and invasion of human pancreatic cancer

Background

Zinc finger RNA binding protein (ZFR) is involved in the regulation of growth and cancer development. However, little is known about ZFR function in pancreatic cancer.

Methods

Herein, to investigate whether ZFR is involved in tumor growth, Oncomine microarray data was firstly used to evaluate ZFR gene expression in human pancreatic tumors. Then short hairpin RNA (shRNA) targeting ZFR was designed and delivered into PANC-1 pancreatic cancer cells to knock down ZFR expression. Cell viability, cell proliferation and cell cycle analysis after ZFR knockdown were determined by MTT, colony forming and FACS, respectively. In addition, cell migration and invasion were assessed using the Transwell system.

Results

The expression of ZFR was significantly higher in pancreatic tumors than normal pancreas tissues by Oncomine database analysis. Knockdown of ZFR by shRNA-expressing lentivirus significantly decreased the viability and invasion ability of pancreatic cancer cells. Moreover, FACS analysis showed that knockdown of ZFR in PANC-1 cells caused a significant cell cycle arrest at G0/G1 phase. Furthermore, knockdown of ZFR decreased the levels of CDK2, CDK4, CyclinA and CyclinD1 and enhanced the expression of p27, which has evidenced by qRT-PCR and Western blot analysis.

Conclusions

Knockdown of ZFR might provide a novel alternative to targeted therapy of pancreatic cancer and deserves further investigation.

Clinical value of serum tumor markers CA19-9, CA125 and CA72-4 in the diagnosis of pancreatic carcinoma

CA125 and CA72-4 are members of a family of high-molecular weight glycosylated proteins and are commonly considered as biomarkers in the diagnosis of ovarian and gastric cancer, respectively. However, recent studies have revealed that these two markers may be of clinical value in the diagnosis of pancreatic cancer. As the availability of data regarding CA72-4 and CA125 in the diagnosis of pancreatic cancer is limited, the aim of this study was to investigate the clinical value of serum tumor markers CA19-9, CA125 and CA72-4 in the diagnosis of pancreatic carcinoma according to logistic regression analysis and receiver operating characteristic (ROC) curves and to investigate the correlation of these markers with tumor TNM stage and location. An immunoradiometric assay was used to measure pre-operative serum CA19-9, CA125 and CA72-4 levels in 75 patients with pancreatic carcinoma and 70 patients with benign pancreatic diseases. The concentrations of serum CA19-9, CA125 and CA72-4 in patients with pancreatic carcinoma were found to be significantly higher (P<0.05) compared with those with benign pancreatic diseases. The combined detection of two serum markers (CA19-9 + CA72-4) yielded a ROC value of 0.895 that was significantly higher compared to others (P<0.05) in distinguishing pancreatic cancer from benign pancreatic diseases. At optimal cut-off, the sensitivity and specificity of combined detection (CA19-9 + CA72-4) were 70.6 and 92.8%, respectively. The concentrations of CA125 and CA19-9 in patients with pancreatic adenocarcinoma were found to be significantly higher (P<0.05) compared with those of pancreatic neuroendocrine carcinoma. In conclusion, the combined detection of CA19-9 and CA72-4) may significantly improve the diagnostic specificity and the serum concentrations of CA125 and CA19-9 are correlated with tumor histological type.

Multivisceral resections in pancreatic cancer: identification of risk factors

BACKGROUND

There is an assumption that multivisceral resections (MVRs) in patients with a pancreatic malignancy are associated with higher morbidity. The oncologic benefit, however, remains controversial.

METHODS

The aim was to identify risk factors for complications in cases of MVR in patients with pancreatic cancer. Of 1099 patients who underwent major pancreatic resection at our institution between January 1992 and October 2008, a total of 55 were treated with an MVR involving resection of one or more additional organs. This group was compared with 154 patients who had palliative bypass surgery and 303 patients who underwent standard pancreatic head resection.

RESULTS

Multivisceral resection patients had an overall higher incidence of major surgical complications (p < 0.001). In-hospital mortality was comparable in all groups. Median survival after MVR was inferior to that after standard resection but was significantly better than that after palliative bypass. Univariate logistic regression analysis identified concomitant colon, kidney, and liver resections and any intraoperative transfusion as predictors of complications; in the multivariate analysis, only kidney resections and any intraoperative transfusion were confirmed predictors. In contrast, T status, kidney resection, resection of four or more organs, any postoperative transfusion, and intensive care unit stay of >2 days were identified as predictors of survival in the univariate Cox regression analysis; in the multivariate analysis, only the T status was confirmed. Median survival after MVR was 16 months, after palliative bypass 6 months, and after standard resection 18 months (p < 0.001).

CONCLUSIONS

Multivisceral resections are technically feasible procedures with increased survival when compared to palliative bypass procedures. The incidence of postoperative complications was increased with kidney resection and when intraoperative transfusion was required.

Dynamic expression of Tbx2 and Tbx3 in developing mouse pancreas

Tbx2 and Tbx3 are closely related members of the T-box family of transcription factors that are important regulators during normal development as well as major contributors to human developmental syndromes when mutated. Although there is evidence for the involvement of Tbx2 and Tbx3 in pancreatic cancer, so far there are no reports characterizing the normal expression pattern of these genes in the pancreas. In this study, we examined spatial and temporal expression of Tbx2 and Tbx3 in mouse pancreas during development and in the adult using in situ hybridization and immunohistochemistry. Our results show that Tbx2 and Tbx3 are both expressed in the pancreatic mesenchyme throughout development beginning at embryonic day (E) 9.5. In addition, Tbx2 is expressed in pancreatic vasculature during development and in epithelial-derived endocrine and ductal cells during late fetal stages, postnatal development and in adult pancreas. In contrast, Tbx3 is expressed in exocrine tissue in the postnatal and adult pancreas. Further our results demonstrate that Tbx2 and Tbx3 are expressed in tumor-derived endocrine and exocrine cell lines, respectively. These dynamic changes in the expression pattern of these transcription factors lay the foundation for investigation of potential roles in pancreas development.

Inhibitory effects of miR-146b-5p on cell migration and invasion of pancreatic cancer by targeting MMP16

Previous studies have shown that miRNAs participate in a wide range of biological functions and play important roles in various human diseases including cancer. We found miR-146b-5p significantly dysregulated in human pancreatic cancer cells by qRT-PCR. To demonstrate its function and regulation mechanism, we overexpressed miR-146-5p by transfecting the mimics. Our data showed that miR-146b-5p overexpression significantly reduced the abilities of migration and invasion of MIA PaCa-2 pancreatic cancer cells. Furthermore, we found that matrix metalloproteinase 16 (MMP16) was a downstream target of miR-146b-5p by dual-luciferase reporter assay. Altogether, our findings suggest that miR-146b-5p may be involved in pancreatic cancer cell migration and invasion by targeting MMP16, and miR-146b-5p may be a potential therapeutic target for the pancreatic cancer.

Suppression of the uPAR-uPA system retards angiogenesis, invasion, and in vivo tumor development in pancreatic cancer cells

Despite existing chemotherapy and surgical resection strategies, pancreatic cancer is one of the major causes of mortality in the United States with a 5-year mean survival rate of less than 5%. The activation of the urokinase-type plasminogen activator receptor-urokinase-type plasminogen activator (uPAR-uPA) system in the development of pancreatic ductal adenocarcinoma has been well established. In the present study, we used 2 pancreatic cancer cell lines, MIA PaCa-2 and PANC-1 to show the effects of uPAR and uPA downregulation. From the results, we observed that RNAi expressing plasmids efficiently downregulated mRNA and protein expression of uPAR and uPA. In vitro and in vivo angiogenic assays revealed a significant decrease in the angiogenic potential of MIA PaCa-2 and PANC-1 cells that were downregulated for both uPAR and uPA. From the angiogenesis antibody array analysis, we observed that the simultaneous downregulation of uPAR and uPA resulted in the downregulation of angiogenin and overexpression of RANTES. Further, FACS analysis showed that the simultaneous downregulation of uPAR and uPA caused the accumulation of cells in the sub-G(0/1) phase in both MIA PaCa-2 and PANC-1 cells. In addition, Western blot analysis revealed that downregulation of uPAR and uPA caused the activation of caspase 8 and CAD, which is indicative of apoptosis, and in vivo TUNEL assay confirmed these results. Finally, we observed the nuclear localization of uPA and that uPA interacts with the transcription factor Lhx-2. Taken together, the results of the present study show that the targeting of the uPAR-uPA system has therapeutic potential.

Effects of IL-6 and AG490 on regulation of Stat3 signaling pathway and invasion of human pancreatic cancer cells in vitro

BACKGROUND

Signal transducer and activator of transcription 3 (Stat3) is a member of the Janus-activated kinase(Jak)/Stat signaling pathway. Abnormal activation of Stat3 plays a critical role in metastasis and invasion in varieties of human tumors including pancreatic cancer. This study aimed to investigate the mechanisms of activation and blocking of the Stat3 signaling pathway and its effects on invasion and metastasis of human pancreatic cancer cells.

METHODS

The Jak inhibitor AG490 and interleukin-6 (IL-6) were added to the culture media of human pancreatic cancer cells SW1990 and Capan-2, respectively. Cell growth was measured by MTT assays. Western blotting and immunocytochemistry were performed to detect phosphorylated Stat3 (p-Stat3) protein, while VEGF and MMP-2 mRNA and protein expression were examined with fluorescence quantitative polymerase chain reaction and Western blotting, respectively. The invasion ability of SW1990 and Capan-2 cells was determined by cell invasion assay.

RESULTS

Stat3 was activated by IL-6 in Capan-2 cells; protein expression of p-Stat3 was increased significantly in Capan-2 cells. IL-6 remarkably promoted the growth of Capan-2 cells (P < 0.05), and VEGF and MMP-2 mRNA and protein expression were increased significantly. Also, IL-6 increased the invasion ability of Capan-2 cells. AG490 inhibited Stat3 activation in SW1990 cells. Western blotting and immunocytochemistry analysis showed that p-Stat3 protein expression was decreased significantly with AG490 treatment in SW1990 cells. AG490 remarkably inhibited the growth of Capan-2 cells (P < 0.05), and VEGF and MMP-2 mRNA and protein expression was decreased significantly. And AG490 decreased the invasion ability of SW1990 cells.

CONCLUSIONS

Abnormal activation of Stat3 plays an important role in the invasion and metastasis of pancreatic cancer. Activation and blocking of the Stat3 signaling pathway can affect invasion ability and expression of the VEGF and MMP-2 genes in pancreatic cancer cells. The Stat3 signaling pathway may provide a novel therapeutic target for treatment of pancreatic cancer.

Defining research priorities for pancreatic cancer in Australia: results of a consensus development process

Introduction

Pancreatic cancer (PC) is the sixth leading cause of cancer death in Australia and the fourth in the United States, yet research in PC is lagging behind that in other cancers associated with a high disease burden. In the absence of agreed processes to reliably identify research areas which can deliver significant advances in PC research, the Cancer Council NSW established a strategic partnership with the NSW Pancreatic Cancer Network to define critical research issues and opportunities that could accelerate progress in this field in Australia.

Materials and methods

The process consisted of five distinct stages: a literature review on recent progress in PC research, semi-structured expert interviews, a Delphi process, consumer focus groups, and a nominal group process. Information collected at each step informed the development of subsequent stages.

Results

The results from these steps were refined by the nominal group into a set of seven specific pancreatic cancer research goals. The goals were disseminated and led to a new funding scheme for key PC research priorities.

Discussion

This prioritisation exercise provided a much needed “road map” for research prioritisation in PC and served as a checklist to researchers applying for PC research grants to confirm how their research can contribute towards accelerating progress in PC research in Australia.

Genetic variation of miRNA sequence in pancreatic cancer

MicroRNAs (miRNAs) are small non-coding RNAs of 20-22 nucleotides (nts) and constitute a novel class of gene regulators that negatively regulate gene expression at the post-transcriptional level. The expression of miRNA is deregulated in many types of cancers. Alterations in miRNA expression may be an important contributor to the development of pancreatic carcinoma. We hypothesized that genetic variations in miRNA genes were associated with pancreatic carcinoma and analyzed genomic sequences coding for the precursors of eight miRNA genes in both pancreatic carcinoma tissues and cancer cell lines. Four novel mutations in primary miRNA transcripts were identified. TaqMan miRNA assays showed that miR-21 was significantly overexpressed in 20 pancreatic carcinomas and 6 cancer cell lines compared with paired benign tissues and normal pancreas. Two mutations of miR-21 did not notably alter the activity of the promoter of the miRNA gene. Although most of these mutations seem to have no effect on miRNA processing, an A-G mutation at 29-nt downstream of pre-miR-21 led to a conformational change of the secondary structure close to the stem reaching into the pre-miR-21 and a relative reduction of the mature miR-21 expression in vivo. These results suggested that miRNA might play an important role in pancreatic tumorigenesis, but the molecular mechanism underlying the particular sequence variations in miRNA that can cause aberrant expression remains to be determined.

Preoperative tissue diagnosis for tumours of the pancreas

BACKGROUND

Preoperative biopsy of pancreatic lesions suspected of malignancy is controversial.

METHODS

A systematic Medline literature search was carried out. Diagnostic studies reporting quantitative preoperative pancreatic biopsy data were evaluated.

RESULTS

The analysis included 53 studies, mostly of a retrospective nature. Despite acceptable rates for sensitivity and specificity, the negative predictive value of percutaneous and endoscopic ultrasonography-guided biopsies was 60-70 per cent. Biopsy results were considered to be essential for directing non-surgical therapy in advanced disease. However, they were of limited value in planning the treatment of resectable solid or cystic tumours, or focal lesions in the setting of chronic pancreatitis.

CONCLUSIONS

Biopsy of suspected pancreatic malignancies with systemic spread or local irresectability is indicated for planning palliative or neoadjuvant therapy. Preoperative biopsy of potentially resectable pancreatic tumours is not generally advisable, as malignancy cannot be ruled out with adequate reliability.

Magnetic resonance imaging monitors physiological changes with antihedgehog therapy in pancreatic adenocarcinoma xenograft model

OBJECTIVES

The sonic hedgehog (Shh) pathway has an established role in pancreatic cancer (pancreatic adenocarcinoma [PDAC]). We tested whether magnetic resonance imaging measures of vascular volume fraction (VVF) using magnetic iron oxide nanoparticles are sensitive to the antiangiogenic effect of targeted Shh therapies in a PDAC xenograft model.

METHODS

Pancreatic adenocarcinoma xenograft lines were subcutaneously implanted into nude mice (n = 19 samples within 4 groups). Therapies were targeted to 3 loci of the Shh signaling pathway (anti-Shh antibody, cyclopamine, or forskolin). Magnetic resonance imaging (4.7-T Bruker Pharmascan) was performed (after 1 week of intraperitoneal therapy) before and after intravenous injection of MION-47. Vascular volume fraction was quantified as DeltaR2 (from multicontrast T2 sequences) and normalized to an assumed VVF in muscle of 3%. Linear regression compared VVF to histological indices including microvessel density (MVD), viable gland density (VGD), and proliferative index (PI).

RESULTS

In response to anti-Hh treatment, tumors showed a decrease in VGD, PI, MVD, and VVF compared with controls (P < 0.001). Vascular volume fraction was compared with histological indicators of response: PI (R2 = 0.88; P < 0.05), VGD (R2 = 0.87; P< 0.05), and MVD (R2 = 0.85; P < 0.05).

CONCLUSIONS

Magnetic resonance imaging VVF using magnetic iron oxide nanoparticles may serve as a noninvasive measure of biological response to Shh PDAC therapy with easy translation to the clinic.

Molecular targeted therapies for pancreatic cancer

BACKGROUND

Pancreatic cancer cells express different mutations that increase the aggressiveness and confer resistance to conventional chemotherapy and radiotherapy. Molecules that selectively bind and inhibit these mutations are effective in other solid tumors and are now emerging as a complementary therapy in pancreatic cancer. The objective of this review is to describe the effect of drugs that inhibit specific mutations present in pancreatic cancer with special emphasis on clinical trials.

DATA SOURCES

We reviewed the English-language literature (MedLine) addressing the role of drugs that target mutations present in pancreatic cancer. Both preclinical and clinical studies were included.

CONCLUSIONS

Preclinical evidence supports the combination of conventional approved therapies plus drugs that block epidermal growth factor receptor and vascular growth endothelial factor or induce apoptosis. However, most of the current clinical evidence is limited to small phase I trials evaluating the toxicity and safety of these regimens. The results of additional randomized trials that are still undergoing will clarify the role of these drugs in pancreatic cancer.

The WSB1 gene is involved in pancreatic cancer progression

Background

Pancreatic cancer cells generate metastases because they can survive the stress imposed by the new environment of the host tissue. To mimic this process, pancreatic cancer cells which are not stressed in standard culture conditions are injected into nude mice. Because they develop xenografts, they should have developed adequate stress response. Characterizing that response might provide new strategies to interfere with pancreatic cancer metastasis.

Methodology/Principal Findings

In the human pancreatic cancer cell lines Panc-1, Mia-PaCa2, Capan-1, Capan-2 and BxPC3, we used Affymetrix DNA microarrays to compare the expressions of 22.000 genes in vitro and in the corresponding xenografts. We identified 228 genes overexpressed in xenografts and characterized the implication of one of them, WSB1, in the control of apoptosis and cell proliferation. WSB1 generates 3 alternatively spliced transcripts encoding distinct protein isoforms. In xenografts and in human pancreatic tumors, global expression of WSB1 mRNA is modestly increased whereas isoform 3 is strongly overexpressed and isoforms 1 and 2 are down-regulated. Treating Mia-PaCa2 cells with stress-inducing agents induced similar changes. Whereas retrovirus-forced expression of WSB1 isoforms 1 and 2 promoted cell growth and sensitized the cells to gemcitabine- and doxorubicin-induced apoptosis, WSB1 isoform 3 expression reduced cell proliferation and enhanced resistance to apoptosis, showing that stress-induced modulation of WSB1 alternative splicing increases resistance to apoptosis of pancreatic cancer cells.

Conclusions/Significance

Data on WSB1 regulation support the hypothesis that activation of stress-response mechanisms helps cancer cells establishing metastases and suggest relevance to cancer development of other genes overexpressed in xenografts.

Pancreatic cancer is 'always non-resectable'

Pancreatic cancer is characterized by its very aggressive biological behavior which makes it a rapidly disseminating and deadly tumor. Due to their initial 'silent' behavior, pancreatic cancers are generally diagnosed too late and at that point surgical or medical interventions are futile. The outcome of pancreatic cancer has not improved over the last decades. It is evident that only very few pancreatic cancers are potentially resectable and curable, but many times even these small cancers have poor prognostic factors. Furthermore, upon surgery many of the patients considered preoperatively to have resectable tumors are found to have non-resectable disease. The problem of pancreatic cancer is further compounded by the fact that most tumors are diagnosed in elderly, frail or chronically ill patients, which makes them poor surgical candidates, and only half or fewer of these patients can undergo surgery. The stress of surgery is poorly tolerated by many patients who either die, develop complications or are then unable to receive adjuvant chemotherapy. The bottom line is that pancreatic cancer is a very aggressive tumor. Currently, most cancers are treated by non-surgical methods, and the very few patients with tumors which are potentially resectable should be operated on in specialized, high-volume pancreatic centers.

Recent advances on the molecular mechanisms involved in pancreatic cancer progression and therapies

This review describes the recent advances in the molecular events involved in pancreatic cancer initiation, progression, and metastasis. Additionally, the importance of deregulated cellular signaling elements as potential targets for developing novel therapeutic strategies against incurable forms of pancreatic cancer is reported. The emphasis is on the critical functions gained by numerous growth factors and their receptors, such as epidermal growth factor receptor, hedgehog signaling, and proangiogenic agents such as vascular endothelial factor and interleukin-8 for the sustained growth, survival, and metastasis of pancreatic cancer cells. The molecular mechanisms associated with antitumoral properties and the clinical benefits of gemcitabine alone or in combination with other cytotoxic agents for the treatment of pancreatic cancer are discussed.

CEACAM6 is a determinant of pancreatic adenocarcinoma cellular invasiveness

Pancreatic adenocarcinoma is among the most aggressively invasive malignancies. The immunoglobulin superfamily member carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is emerging as an important determinant of the malignant phenotype in a range of cancers. We sought to define the role of CEACAM6 in pancreatic adenocarcinoma cellular invasiveness. CEACAM6 was stably overexpressed in Capan2 cells, which inherently express low levels of CEACAM6. Retrovirally mediated RNA interference was used to silence CEACAM6 expression in BxPC3 cells, which inherently overexpress CEACAM6. Cellular invasiveness was quantified using a modified Boyden chamber assay. Overexpression of CEACAM6 increased Capan2 cellular invasiveness, whereas CEACAM6 knockdown attenuated BxPC3 invasiveness. A role for the c-Src tyrosine kinase in mediating CEACAM6-dependent invasiveness was defined using constitutively active and dominant-negative c-Src expression constructs. c-Src-dependent modulation of matrix metalloproteinase-9 activity contributes significantly to the increased cellular invasiveness induced by CEACAM6 overexpression. Levels of CEACAM6 expression can modulate pancreatic adenocarcinoma cellular invasiveness in a c-Src-dependent manner. This pathway warrants further investigation as a target for therapy.