Naturally occurring K vitamins inhibit pancreatic cancer cell survival through a caspase‐dependent pathway

Background and Aims: Available medical therapies against pancreatic cancer are largely ineffective and have many side‐effects. Physiologically, vitamins K1 and K2 (VK) act as co‐factors for γ‐carboxylation of prothrombin and other coagulation factors. In previous studies, VK analogs have been found to have potent negative effects on the survival of various cancer cells. We hypothesized that the well‐tolerated and naturally occurring VK1 and VK2 may be used to inhibit pancreatic cancer cell survival. Methods: Four pancreas cancer cell lines were tested. Two of these (MiaPaCa2 and PL5) were found to be sensitive to VK1 and VK2 (IC50 values ≤150 µM). To address the mechanisms of this effect on cell survival, we performed cell cycle and apoptosis studies using VK2 (the more potent compound). Results: We found that VK induced caspase‐dependent apoptosis in over 60% of cells in the sensitive lines at the half maximal inhibitory concentration (IC₅₀) range. Further, this induction in apoptosis was antagonized by a caspase inhibitor. Accompanying apoptosis, a dose‐ and time‐dependent induction of extracellular signal‐regulated kinase (ERK) phosphorylation occurred when sensitive lines were treated with either VK1 or VK2 at inhibitory doses. Simultaneous co‐treatment of cells with a MEK1 inhibitor and VK prevented both the induction of ERK phosphorylation and the apoptosis, showing that the mitogen‐activated protein (MAP) kinase pathway is central for VK‐mediated apoptosis in pancreatic cancer cells. Conclusion: These data show that naturally‐occurring, non‐toxic K vitamins can inhibit the survival of some pancreatic cancer cell lines. These novel, safe and clinically‐utilized agents initiate a caspase‐dependent apoptosis via the MAP kinase pathway and could potentially benefit patients with pancreatic cancer either as a single agent or in combination with chemotherapy for treatment, or for prevention of recurrence of pancreas cancer post resection.     

Selection criteria in resectable pancreatic cancer: A biological and morphological approach

Pancreatic ductal adenocarcinoma (PDA) remains one of the most aggressive tumors with a low rate of survival. Surgery is the only curative treatment for PDA, although only 20% of patients are resectable at diagnosis. During the last decade there was an improvement in survival in patients affected by PDA, possibly explained by the advances in cancer therapy and by improve patient selection by pancreatic surgeons. It is necessary to select patients not only on the basis of surgical resectability, but also on the basis of the biological nature of the tumor. Specific preoperative criteria can be identified in order to select patients who will benefit from surgical resection. Duration of symptoms and level of carbohydrate antigen 19.9 in resectable disease should be considered to avoid R1 resection and early relapse. Radiological assessment can help surgeons to distinguish resectable disease from borderline resectable disease and locally advanced pancreatic cancer. Better patient selection can increase survival rate and neoadjuvant treatment can help surgeons select patients who will benefit from surgery.     

Significance of the inflammation-based prognostic score in recurrent pancreatic cancer

BackgroundAlthough the prognosis of recurrent pancreatic cancer (RPC) is improving with the appearance of new anticancer drugs, prognostic indicators for RPC are still poorly understood. The aim of this study was to evaluate significance of the inflammation-based prognostic score, including modified Glasgow Prognostic Score (mGPS), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), and Prognostic Nutritional Index (PNI), in patients with RPC.MethodsThis study reviewed 263 patients of pancreatic ductal adenocarcinoma at our institution between 2006 and 2015. A receiver operating characteristics curve analysis was performed to determine the cut-off values. The prognostic significance of the inflammation-based prognostic scores were evaluated by a multivariate analysis.Results172 patients (65.4%) who had recurrence was included in this study. The optimal PNI for predicting 1-year survival after recurrence was 40 with higher area under receiver operating characteristics curve value (0.704) in comparison with other inflammation-based prognostic scores. A univariate and multivariate analysis revealed that liver metastasis (P < 0.001) and PNI < 40 (P < 0.001) were independently associated with the survival time after recurrence. When each of the two predictors was counted as one point and the points were calculated for all cases, a good stratified survival curve was obtained, showing the shorter survival in the higher points: median survival times of 2, 1, and 0 points were 4.3, 11.1, and 21.2 months, respectively (P < 0.001).ConclusionsInflammation-based prognostic scores, especially PNI is useful clinical biomarker for predicting the survival time after recurrence in patients with pancreatic adenocarcinoma.     

Improving the accuracy of pancreatic cancer clinical staging by exploitation of nanoparticle-blood interactions: A pilot study

Background

Pancreatic ductal adenocarcinoma (PDAC) early diagnosis is? crucial ?and new, cheap and user-friendly techniques for biomarker identification? are ?needed. “Protein corona” (PC) is emerging a new bio-interface potentially useful in tumor early diagnosis. In a previous investigation, we showed that relevant differences between the ?protein patterns of? PCs formed on lipid NPs after exposure to PDAC and non-cancer plasma? samples exist. To extend that research, We performed this pilot study to investigate the effect of PDAC tumor size and distant metastases on PC composition.

ATG7 is a haploinsufficient repressor of tumor progression and promoter of metastasis

The role of autophagy in cancer is complex. Both tumor-promoting and tumor-suppressive effects are reported, with tumor type, stage and specific genetic lesions dictating the role. This calls for analysis in models that best recapitulate each tumor type, from initiation to metastatic disease, to specifically understand the contribution of autophagy in each context. Here, we report the effects of deleting the essential autophagy gene Atg7 in a model of pancreatic ductal adenocarcinoma (PDAC), in which mutant Kras^G12D and mutant Trp53^172H are induced in adult tissue leading to metastatic PDAC. This revealed that Atg7 loss in the presence of Kras^G12D/+ and Trp53^172H/+ was tumor promoting, similar to previous observations in tumors driven by embryonic Kras^G12D/+ and deletion of Trp53. However, Atg7 hemizygosity also enhanced tumor initiation and progression, even though this did not ablate autophagy. Moreover, despite this enhanced progression, fewer Atg7 hemizygous mice had metastases compared with animals wild type for this allele, indicating that ATG7 is a promoter of metastasis. We show, in addition, that Atg7^+/− tumors have comparatively lower levels of succinate, and that cells derived from Atg7^+/− tumors are also less invasive than those from Atg7^+/+ tumors. This effect on invasion can be rescued by ectopic expression of Atg7 in Atg7^+/− cells, without affecting the autophagic capacity of the cells, or by treatment with a cell-permeable analog of succinate. These findings therefore show that ATG7 has roles in invasion and metastasis that are not related to the role of the protein in the regulation of autophagy.

The preservation of cellular integrity and the ability to adapt to different forms of cellular stress are key in the prevention of various forms of disease. Autophagy constitutes a group of processes that facilitates these goals by delivering cellular constituents to lysosomes for degradation and recycling (1). The cargoes destined for degradation can either be targeted specifically to promote cellular health and integrity, or simply digested nonselectively in response to cellular cues such as nutrient deprivation or tissue remodeling (1).The best characterized form of autophagy is macroautophagy, which is often and hereafter referred to more simply as autophagy. Autophagy involves a number of evolutionarily conserved ATG proteins that orchestrate the formation of a double-membraned structure called an autophagosome which sequesters cellular cargo (2, 3). Autophagosomes then traffic to and fuse with lysosomes to form another structure termed the autolysosome, within which degradation occurs (1). The ability to understand the function of autophagy has been facilitated by the identification that a number of ATG proteins, including ATG7 and ATG5, are essential for autophagosome formation, and mice containing floxed alleles for the genes encoding these proteins have been fundamental in understanding the role of autophagy in various forms of mammalian physiology and disease (2–5).It is now clear that autophagy has a major role in both preventing and sustaining cancer (6). Several autophagy genes have been shown to be mutated in major forms of cancer, and mice lacking autophagy genes have been shown to be tumor prone (7–9). Studies have indicated, however, that the role of autophagy in cancer can depend on tumor type, the stage of tumor development, and the specific genetic mutations associated with disease progression (10–13). The current consensus is that autophagy has a tumor suppressive role before or in the early stages of tumor development when protecting cellular fidelity is fundamental in preventing cancer initiation and early progression (6, 14). In established tumors, however, autophagy generally appears to have a tumor supportive role (6, 14). Within the highly stressed environment of an established tumor, it is considered that autophagy mitigates this stress to permit tumor cell survival under these conditions.A tumor type in which autophagy has been studied extensively is pancreatic ductal adenocarcinoma (PDAC). Using a genetically engineered mouse model (GEMM) of PDAC, it was reported that PDAC development driven by mutant KRAS was dependent on autophagy (10, 15, 16). This was, however, found to be different in PDAC driven by KRAS and the absence of p53 in which the loss of autophagy was tumor-promoting (10). In contrast to these findings, studies of patient-derived xenografts (PDX) formed in immuno-compromised mice indicated that inhibition of autophagy impaired tumor formation irrespective of p53 status (16). In human PDAC when p53 is perturbed, the TP53 gene is usually mutated and retained rather than deleted/silenced, and the genetic lesions associated with the disease occur at focal sites within the adult pancreas rather than being expressed from embryonic development as is the case with most GEMM models (17). We therefore decided to analyze autophagy—by conditional deletion of the essential autophagy gene Atg7—in a mouse model of PDAC involving alleles for mutant Kras^G12D and mutant Trp53^172H, which are recombined in the adult using an inducible Cre recombinase driven by the pancreas selective promoter Pdx1. These mice undergo the full spectrum of tumor development from initiation to metastatic disease and our studies using these animals provide further insights into the relationship between Trp53 and loss of Atg7 and also highlight disparate roles for ATG7 and autophagy during tumor development.     

Predictive factors of survival in patients with borderline resectable pancreatic cancer who received neoadjuvant therapy

Background/objectivesThis study aimed to develop the prognostic score (PS) based on clinical factors to stratify the prognosis in borderline resectable pancreatic cancer (BRPC) patients treated with neoadjuvant therapy (NAT).MethodsThis retrospective study included 57 BRPC patients who received NAT between April 2012 and December 2017. A score was assigned to each prognostic factor available before and after NAT, according to their β coefficients.ResultsMultivariate analysis identified the following six prognostic factors, and scores were assigned as follows: being a familial PC patient (HR 4.98, p = 0.029), post-NAT CA19-9 ≥37 U/ml (HR 3.08, p = 0.020), reduction rate of CA19-9 <70% (HR 3.71, p = 0.008), pre-NAT neutrophil-to-lymphocyte ratio ≥2.8 (HR 4.32, p = 0.003), and non-resection (HR 3.98, p = 0.009) were scored as 1; and post-NAT albumin-to-globulin ratio <1.33 (HR 8.31, p < 0.001) was scored as 2. The PS was calculated by summing the scores assigned to each prognostic factor. Patients were then classified into three risk groups (low- [0–1 points], moderate- [2–3 points], and high-risk [4–6 points] groups). Median overall survival in the low-, moderate-, and high-risk groups were not reached, 37.5 months, and 11.8 months, respectively, and there were significant differences in survival among the three groups (p < 0.01 in each group).ConclusionsThis study showed that the PS may be useful for predicting the prognosis of BRPC patients treated with NAT.     

银杏素通过激活Nrf2/SLC7A11/GPX4信号通路抑制ox-LDL诱导的血管内皮细胞铁死亡

[目的]探讨银杏素调节核因子E2相关因子2(Nrf2)/溶质载体家族7成员11(SLC7A11)/谷胱甘肽过氧化物酶4(GPX4)信号通路对氧化型低密度脂蛋白(ox-LDL)诱导的血管内皮细胞铁死亡的影响。[方法]将人脐静脉内皮细胞EA.hy926分为正常对照组(正常培养)、ox-LDL组(50 mg/L ox-LDL)、银杏素低剂量组(50 mg/L ox-LDL+10μmol/L银杏素)、银杏素中剂量组(50 mg/L ox-LDL+20μmol/L银杏素)、银杏素高剂量组(50 mg/L ox-LDL+40μmol/L银杏素)、ML385组(50 mg/L ox-LDL+40μmol/L银杏素+1μmol/L的Nrf2抑制剂ML385)、Erastin组(50 mg/L ox-LDL+40μmol/L银杏素+5μmol/L的SLC7A11抑制剂Erastin)、RSL3组(50 mg/L ox-LDL+40μmol/L银杏素+0.5μmol/L的GPX4抑制剂RSL3);MTT法检测细胞存活率;试剂盒检测细胞超氧化物歧化酶(SOD)、丙二醛(MDA)、还原型谷胱甘肽(GSH)水平...     

Overexpression of pancreatitis-associated protein (PAP) in human pancreatic ductal adenocarcinoma

Pancreatitis-associated protein (PAP) is almost absent in normal pancreas, but is strongly induced in acute pancreatitis. PAP mRNA is also expressed in cancer cells, including pancreatic ductal adenocarcinoma. However, the clinicopathological significance of PAP in human pancreatic cancer is not clear. We examined PAP expression in pancreatic tissues from individuals with pancreatic ductal adenocarcinoma using immunohistochemistry. PAP was overexpressed in 79% (30 of 38) of pancreatic ductal adenocarcinoma, 19% (7 of 36) of chronic pancreatitis, and 29% (2 of 7) of mucinous cystadenoma. PAP was found in malignant ductular structures in pancreatic carcinomas as well as in benign proliferating ductules and acinar cells in chronic pancreatitis. It was not expressed in normal pancreas. The incidence of PAP overexpression was significantly higher in pancreatic cancer than in the other pancreatic diseases (P < 0.01). PAP overexpression was significantly correlated with nodal involvement, distant metastasis (P < 0.05), and short survival (P < 0.01) in pancreatic cancer. These results suggest that overexpression of PAP in human pancreatic ductal adenocarcinoma indicates tumor aggressiveness.     

Management of pancreatic cancer in the elderly

Currently, pancreatic adenocarcinoma mainly occurs after 60 years of age, and its prognosis remains poor despite modest improvements in recent decades. The aging of the population will result in a rise in the incidence of pancreatic adenocarcinoma within the next years. Thus, the management of pancreatic cancer in the elderly population is gaining increasing relevance. Older cancer patients represent a heterogeneous group with different biological, functional and psychosocial characteristics that can modify the usual management of this disease, including pharmacokinetic and pharmacodynamic changes, polypharmacy, performance status, comorbidities and organ dysfunction. However, the biological age, not the chronological age, of the patient should be the limiting factor in determining the most appropriate treatment for these patients. Unfortunately, despite the increased incidence of this pathology in older patients, there is an underrepresentation of these patients in clinical trials, and the management of older patients is thus determined by extrapolation from the results of studies performed in younger patients. In this review, the special characteristics of the elderly, the multidisciplinary management of localized and advanced ductal adenocarcinoma of the pancreas and the most recent advances in the management of this condition will be discussed, focusing on surgery, chemotherapy, radiation and palliative care.     

Ablation of sensory neurons in a genetic model of pancreatic ductal adenocarcinoma slows initiation and progression of cancer

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an exuberant inflammatory desmoplastic response. The PDAC microenvironment is complex, containing both pro- and antitumorigenic elements, and remains to be fully characterized. Here, we show that sensory neurons, an under-studied cohort of the pancreas tumor stroma, play a significant role in the initiation and progression of the early stages of PDAC. Using a well-established autochthonous model of PDAC (PKC), we show that inflammation and neuronal damage in the peripheral and central nervous system (CNS) occurs as early as the pancreatic intraepithelial neoplasia (PanIN) 2 stage. Also at the PanIN2 stage, pancreas acinar-derived cells frequently invade along sensory neurons into the spinal cord and migrate caudally to the lower thoracic and upper lumbar regions. Sensory neuron ablation by neonatal capsaicin injection prevented perineural invasion (PNI), astrocyte activation, and neuronal damage, suggesting that sensory neurons convey inflammatory signals from Kras-induced pancreatic neoplasia to the CNS. Neuron ablation in PKC mice also significantly delayed PanIN formation and ultimately prolonged survival compared with vehicle-treated controls (median survival, 7.8 vs. 4.5 mo; P = 0.001). These data establish a reciprocal signaling loop between the pancreas and nervous system, including the CNS, that supports inflammation associated with oncogenic Kras-induced neoplasia. Thus, pancreatic sensory neurons comprise an important stromal cell population that supports the initiation and progression of PDAC and may represent a potential target for prevention in high-risk populations.Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with a median survival of ∼6 mo from diagnosis (National Cancer Institute). A number of unique features distinguish PDAC from other carcinomas, but the most striking is the exuberant desmoplastic infiltrate within tumors. This compartment exhibits an array of cell types, including activated myofibroblasts and myeloid-derived cells. Indeed, this inflammatory infiltrate is present at the inception of neoplasia and accumulates at a near exponential rate during progression to carcinoma and tumor formation. It provides a complex balance of pro- and antitumorigenic signals to neoplastic cells (and also to each other) that is a focus of intense investigation. The pancreas tumor microenvironment has been studied previously, but new tools [genetically engineered mouse models (GEMs) that faithfully recapitulate the salient features of human PDAC] now allow for a careful dissection of the stroma. Using these models, we showed that generalized inflammation is required for the development of precancerous pancreatic intraepithelial neoplasias (1) and that Hedgehog-dependent stromal elements, including activated myofibroblasts, serve to constrain tumor growth and spread (2). Other cellular components of the pancreatic inflammatory stroma have not been examined, and it is possible they also contribute to the complex balance of inputs, supportive and inhibitory, which underlie tumorigenesis and progression.Previous reports indicate sensory neurons have a central role in benign inflammatory disease of the pancreas. Like most abdominal organs, the pancreas is innervated by sensory fibers from both the nodose (via the vagal nerve) and spinal ganglia (via splanchnic nerves) (3–7). In rodent models of acute or chronic pancreatitis, blockade of primary afferents from both nodose and spinal ganglia can moderate or prevent inflammation (8, 9) as well as associated pathology, even if done after the inciting injury (10, 11). In addition, autonomic neurons (sympathetic, parasympathetic, and enteric) (12) innervate the pancreas and interact with sensory fibers.Because of the documented role of sensory neurons in the pathogenesis of pancreatitis (8–11, 13–15), a known contributor to the pathogenesis of PDAC, we hypothesized that sensory neurons innervating the pancreas provide key proinflammatory inputs that support the early stages of tumorigenesis. Here, using GEMs of PDAC, we provide evidence that bidirectional communication between the pancreas and sensory neurons is active well before the establishment of tumors. We detected inflammation in the spinal cord when histologically only precancerous lesions (pancreatic intraepithelial neoplasia, PanIN) were present. This was accompanied by perineural invasion (PNI) of sensory ganglia and spinal cord and evidence of injury to pancreatic sensory and sympathetic neurons. Ablation of sensory neurons at postnatal days 1–2 prevented injury to peripheral neurons and spinal cord inflammation. Surprisingly, sensory neuron ablation was associated with a dose-dependent and dramatic prolongation of survival in PDAC mice. The animals with the greatest degree of capsaicin-induced neuronal ablation (>80%) did not develop cancer (up to 18 mo when they were euthanized for analysis), whereas more than 90% of untreated mice succumbed to PDAC within 6 mo. These studies indicate that sensory neurons contribute significantly to the initiation and progression of PDAC and may be required for the development of this disease.     

Nab-paclitaxel and gemcitabine for the treatment of patients with metastatic pancreatic cancer

Adenocarcinoma of the pancreas or pancreatic cancer as we will refer to it here, is a cancer of poor prognosis with a high mortality, particularly in the advanced or metastatic setting. Until 2011 and the Phase III results of FOLFIRINOX, standard treatment options were limited to gemcitabine. Combination therapy had shown either a lack of or very limited improvement versus monotherapy with gemcitabine. With the positive results of the MPACT study in 2013 showing improved survival with nab-paclitaxel plus gemcitabine combination therapy, there are now more options for oncologists to treat patients with advanced pancreatic cancer. This paper will highlight the Phase I/II and Phase III trials of nab-paclitaxel plus gemcitabine along with discussing their biology and further possible development in treating patients with pancreatic cancer.     

Gene expression analysis of embryonic pancreas development master regulators and terminal cell fate markers in resected pancreatic cancer: A correlation with clinical outcome

Background

Despite the recent introduction of new drugs and the development of innovative multi-target treatments, the prognosis of pancreatic ductal adenocarcinoma (PDAC) remains very poor. Even when PDAC is resectable, the rate of local or widespread disease recurrence remains particularly high. Currently, reliable prognostic biomarkers of recurrence are lacking. We decided to explore the potential usefulness of pancreatic developmental regulators as biomarkers of PDAC relapse.

胰腺癌细胞外吉西他滨耐药机制的研究进展

胰腺癌是预后最差的实体恶性肿瘤,其中约90％是胰腺导管腺癌(pancreatic ductal adenocarcinoma,PDAC).尽管手术切除是唯一可能治愈PDAC的手段,但术后总体生存率不容乐观.因此,以吉西他滨(gemcitabine,GEM)为基础的化疗仍是PDAC最重要的治疗选择之一.然而,GEM单药治...     

Notch2 is required for progression of pancreatic intraepithelial neoplasia and development of pancreatic ductal adenocarcinoma

Pancreatic cancer is one of the most fatal malignancies lacking effective therapies. Notch signaling is a key regulator of cell fate specification and pancreatic cancer development; however, the role of individual Notch receptors and downstream signaling is largely unknown. Here, we show that Notch2 is predominantly expressed in ductal cells and pancreatic intraepithelial neoplasia (PanIN) lesions. Using genetically engineered mice, we demonstrate the effect of conditional Notch receptor ablation in Kras^G12D-driven pancreatic carcinogenesis. Deficiency of Notch2 but not Notch1 stops PanIN progression, prolongs survival, and leads to a phenotypical switch toward anaplastic pancreatic cancer with epithelial–mesenchymal transition. By expression profiling, we identified increased Myc signaling regulated by Notch2 during tumor development, placing Notch2 as a central regulator of PanIN progression and malignant transformation. Our study supports the concept of distinctive roles of individual Notch receptors in cancer development.