Silencing of tumoral carbohydrate sulfotransferase 15 reactivates lymph node pancreatic cancer T cells in mice.

Limited intratumoral T-cell infiltration in pancreatic ductal adenocarcinoma (PDAC) is an obstacle to immunotherapy, yet the efficient approach to enhance tumor-infiltrating T cells is not fully established. Here, we show that tumor-specific knockdown of carbohydrate sulfotransferase 15 (CHST15), a tumor stromal proteoglycan-synthetic enzyme, suppresses tumor growth in a T-cell-dependent manner in a murine model of PDAC. Silencing of tumoral CHST15 unexpectedly expanded CD4+ and CD8+ T cells in tumor draining LN (TDLN), leading to accelerated accumulation of EdU+ proliferating CD4+ and CD8+ T cells and granzyme B+ CD8+ T cells in the tumor. RNA expression analysis indicated that tumoral CHST15 knockdown (KD) downregulated matrix remodeling-related genes, while upregulated anti-tumor T-cell activity-related genes in both tumor and TDLN. CHST15 KD significantly diminished intratumoral and TDLN Ly6C/G+ myeloid-derived suppressor cells prior to TDLN T-cell expansion, suggesting that tumoral CHST15 remotely regulated myeloid-derived suppressor cell mediated T-cell suppression in the TDLN. Our findings illustrate a novel immunotherapeutic potential of tumoral CHST15 blockage by reactivating T cells in immune suppressive TDLN of PDAC.

Phosphorylation of hTERT at threonine 249 is a novel tumor biomarker of aggressive cancer with poor prognosis in multiple organs.

Recent evidence indicates that RNA-dependent RNA polymerase (RdRP) activity of human telomerase reverse transcriptase (hTERT) regulates expression of target genes and is directly involved in tumor formation in a telomere-independent manner. Non-canonical function of hTERT has been considered as a therapeutic target for cancer therapy. We have previously shown that hTERT phosphorylation at threonine 249 (p-hTERT), which promotes RdRP activity, is an indicator of an aggressive phenotype and poor prognosis in liver and pancreatic cancers, using two cohorts with small sample sizes with polyclonal p-hTERT antibody. To clarify the clinical relevance of p-hTERT, we developed a specific monoclonal antibody and determined the diagnostic and prognostic value of p-hTERT in cancer specimens using a large cohort. A monoclonal antibody for phosphorylated hTERT (p-hTERT) at threonine 249 was developed and validated. The antibody was used for the immunohistochemical staining of formalin-fixed, paraffin-embedded specimens from 1523 cases of lung, colon, stomach, pancreatic, liver, breast, and kidney cancers. We detected elevated p-hTERT expression levels in cases with a high mitotic activity, high pathological grade, and high nuclear pleomorphism. Elevated p-hTERT expression was an independent prognostic factor for lung, pancreatic, and liver cancers. Furthermore, p-hTERT expression was associated with immature and aggressive features, such as adenosquamous carcinoma (lung and pancreas), invasive type of cancer (lung), high serum alpha-fetoprotein level (liver), and triple-negative status (breast). In conclusion, RdRP activity indicated by p-hTERT expression predicts aggressive cancer phenotypes in various types of cancer. Thus, p-hTERT is a novel biomarker for the diagnosis of aggressive cancers with a poor prognosis. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Estrogen Receptor-ß Gene Cytosine-Adenine (ESR2-CA) Repeat Polymorphism in Postmenopausal Colon Cancer.

The pathobiological role of estrogen is controversial in colorectal cancer. Cytosine-adenine (CA) repeat in the estrogen receptor (ER)-ß gene (ESR2-CA) is a microsatellite, as well as representative of ESR2 polymorphism. Though its function is unknown, we previously showed that a shorter allele (germline) increased the risk of colon cancer in older women, whereas it decreased it in younger postmenopausal women. ESR2-CA and ER-ß expressions were examined in cancerous (Ca) and non-cancerous (NonCa) tissue pairs from 114 postmenopausal women, and comparisons were made considering tissue types, age/locus, and the mismatch repair protein (MMR) status. ESR2-CA repeats <22/≥22 were designated as 'S'/'L', respectively, resulting in genotypes SS/nSS (=SL&LL). In NonCa, the rate of the SS genotype and ER-ß expression level were significantly higher in right-sided cases of women ≥70 (≥70Rt) than in those in the others. A decreased ER-ß expression in Ca compared with NonCa was observed in proficient-MMR, but not in deficient-MMR. In NonCa, but not in Ca, ER-ß expression was significantly higher in SS than in nSS. ≥70Rt cases were characterized by NonCa with a high rate of SS genotype or high ER-ß expression. The germline ESR2-CA genotype and resulting ER-ß expression were considered to affect the clinical characteristics (age/locus/MMR status) of colon cancer, supporting our previous findings.

Autopsy study examining non-chronic kidney disease versus chronic kidney disease caused by hypertensive-nephrosclerosis in elderly subjects.

BACKGROUND: The aim of this autopsy study was to clarify the differences of renal histopathology between non-chronic kidney disease (CKD) and CKD caused by hypertensive-nephrosclerosis in the elderly and during the aging process. METHODS: We examined autopsy specimens from 105 elderly patients (53 male subjects; mean age, 86.2 years) including 44 patients with CKD as a result of nephrosclerosis. The analysis was divided into two groups depending on whether they had CKD. RESULTS: The incidences of arterial intimal thickening (AIT), obsolescent-type global glomerulosclerosis (OB), and interstitial fibrosis and tubular atrophy (IF/TA) were higher in the CKD group than in the non-CKD group (all p < 0.01). These factors were all correlated with each other (AIT vs. OB, r = 0.43; AIT vs. IF/TA, r = 0.25; OB vs. IF/TA, r = 0.53). IF/TA had the strongest association with hypertension and decreased eGFR. In the non-CKD group, the frequency of OB was more than 20% in subjects aged 90 years or older. However, the individuals in the non-CKD group tended to have compensatory glomerular hypertrophy with increasing age and a retained eGFR, while the CKD group was unable to obtain compensatory hypertrophy and had a lower eGFR. We also found that AIT, OB and IF/TA occurred independently of systemic atherosclerosis. CONCLUSIONS: Non-CKD in the elderly refers to the so-called aging kidney. The progression from aging kidney to CKD caused by nephrosclerosis was influenced by increases in AIT, OB and IF/TA. IF/TA was thought to be the most important downstream factor in the progression of aging kidney to CKD.

Cytological scoring for pancreatic specimens obtained by endoscopic ultrasound-guided fine needle aspiration.

OBJECTIVE: Cytological diagnosis of pancreatic specimens obtained by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is often challenging because of the small sample size or well-differentiated adenocarcinoma with weak cytological atypia. Therefore, the sensitivity and specificity of cytological diagnosis for pancreatic cancer should be improved. Hence, we aimed to clarify the utility of cytological scoring to distinguish malignant from benign lesions for cytological diagnosis of pancreatic EUS-FNA specimens. METHODS: Seven reviewers, including four cytotechnologists and three medical doctors, evaluated 20 morphological indices in pancreatic specimens obtained by EUS-FNA (malignant, n = 111; benign, n = 31). Statistical analyses were performed using Fisher's exact test, logistic regression analysis, the area under the receiver operating characteristic curve, and Youden index. RESULTS: Among the 20 indices, there was a high incidence rate (>40%) of the following 13 indices in malignant cases: irregular structure, hyperchromatic nucleus, irregular cell polarity, unclear cell boundaries, nuclear membrane thickening, anisonucleosis, overlapping, irregular nuclei, high nuclear-cytoplasmic ratio, binding decline, the simultaneous appearance of malignant and benign cells, enlarged nucleoli, and background necrosis. When we diagnosed pancreatic specimens using these 13 cytological indices, the cut-off value of 8/9 showed the highest Youden index (0.950) as well as high sensitivity and specificity in distinguishing malignant from benign specimens (98% and 97%, respectively). CONCLUSION: Thirteen cytological indices showed high sensitivity and specificity in differentiating malignant and benign lesions using pancreatic EUS-FNA samples. All 13 indices were important for diagnosing malignancy in the pancreatic cytology smear of EUS-FNA. Further validation studies are required.

Reproducibility and prognostic significance of area of residual tumor (ART) in post-neoadjuvant resections of pancreatic ductal adenocarcinoma.

BACKGROUND: The pathologic assessments of tumor response after neoadjuvant chemoradiotherapy (NACRT) are critical to improving the prognostic stratification for patients with pancreatic ductal adenocarcinoma (PDAC). Here we clarified the utility of our new grading system based on the area of residual tumor (ART) as compared to existing systems, such as the College of American Pathologists (CAP) and MD Anderson (MDA) score. METHODS: Eight reviewers individually evaluated the tumor regression grade of 30 patients with PDAC based on three types of grading systems. The interobserver concordance and clinicopathological characteristics were compared between the three systems. RESULTS: The interobserver concordance (kappa value) of the ART, CAP, and MDA score were 0.61, 0.48, and 0.53, respectively. Discrepant cases, which were 27% of the cases, exhibited smaller tumor and tumor bed sizes than concordant cases. The reduction in tumor size evaluated by microscopy showed a correlation with the rate of change in carcinoembryonic antigen (CEA) level, CA19-9 level, and tumor size on computed tomography (CT). The ART score was correlated with the tumor size on CT before and after NACRT and disease-free survival. The CAP and MDA scores were not associated with prognosis. CONCLUSION: The ART grading system may be the most practical system to assess the tumor response in post-NACRT resections of PDAC.

Involvement of Nestin in the Progression of Canine Mammary Carcinoma.

Nestin, a class VI intermediate filament protein, is known to be expressed in various types of human neoplasms, including breast cancer, and is associated with their progression. However, its expression and role in canine mammary tumors remain unknown. We analyzed nestin expression in canine mammary tumors using in situ hybridization and immunohistochemistry. We also investigated its role in a canine mammary carcinoma cell line using RNA interference. Nestin expression was not observed in luminal epithelial cells of any of the 62 cases of benign mammary lesions examined, although myoepithelial cells showed its expression in most cases. In 16/50 (32%) primary mammary carcinomas and 6/15 (40%) metastases of mammary carcinomas, cytoplasmic nestin expression was detected in luminal epithelial cells. In luminal cells of primary mammary carcinomas, its expression was positively related to several pathological parameters that indicate high-grade malignancy, including histological grading (P < .01), vascular/lymphatic invasion (P < .01), Ki-67 index (P < .01), and metastasis (P < .05). Immunohistochemistry revealed that nestin expression was related to vimentin expression in mammary carcinomas (P < .01). This relationship was confirmed using reverse transcription-quantitative polymerase chain reaction using 9 cell lines derived from canine mammary carcinoma (P < .01). Finally, nestin knockdown in canine mammary carcinoma cells using small interfering RNA inhibited cell proliferation and migration based on WST-8, Boyden chamber, and cell-tracking assays. These findings suggest that nestin may at least partially mediate these behaviors of canine mammary carcinoma cells.

Serum Exosomal Gamma-Glutamyltransferase Activity Increased in Patients with Renal Cell Carcinoma with Advanced Clinicopathological Features.

BACKGROUND: There has been no clinically useful diagnostic or prognostic biomarker for renal cell carcinoma (RCC). Serum γ-glutamyltransferase (GGT) activity has been reported to be a prognostic marker for several types of cancer including RCC. Exosomes or small extracellular vesicles present in body fluids have potential as a biomarker. We have recently demonstrated that GGT activity on exosomes isolated from serum is useful for the differential diagnosis of prostate cancer and benign prostate hyperplasia. In this study, we aimed to examine if serum exosomal GGT activity could be a marker for RCC. METHODS: We examined GGT1 expression and GGT activity in cell lysates and exosomes from culture medium of HK-2 proximal tubule epithelial and RCC cell lines. GGT activity was measured using a fluorescent probe for GGT, γ-glutamyl hydroxymethyl rhodamine green. Serum and serum exosomal GGT activities were measured in patients with RCC. GGT1 expression in RCC tissues was evaluated by immunohistochemical staining. RESULTS: GGT1 levels in exosomes from KMRC-1, OS-RC-2 and 786-O cells were elevated compared with those from HK-2 cells. In exosomes, GGT1 expression correlated with GGT activity determined using a fluorescent probe for GGT. In RCC patients, serum exosomal GGT activity was elevated in those with advanced stages (III/IV vs. I/II, p = 0.037) and those with microvascular invasion (with vs. without, p = 0.034). Immunohistochemical analysis showed that membranous GGT1 expression was increased in RCC with microvascular invasion. Notably, preoperative serum exosomal GGT activity could predict the likelihood of having microvascular invasion diagnosed by pathological examination of surgically resected specimens. CONCLUSIONS: Our results suggest that serum exosomal GGT activity could be a clinically useful marker for advanced clinicopathological features of RCC patients, and its combined use with conventional diagnostic modalities may improve the diagnosis and treatment of patients.

Lung proliferative lesion-promoting effects of left pulmonary ligation in A/J female mice.

This present study was conducted in an attempt to examine proliferative lesion-promoting effect in the lung by compensatory lung growth after left pulmonary ligation. To examine a strong proliferative lesion-promoting effect in the lung, the effects of left pulmonary ligation on lung proliferative lesions induced by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) were examined for 12 weeks. The number of proliferative lesions induced by NNK in the right lung after left pulmonary ligation increased significantly after 12 weeks, indicated by an increase in the weight of the right lung. In addition, several messenger RNA (mRNA) markers, including insulin growth factor 1, were highly expressed in the right lung on the seventh day after left ligation. These experiments demonstrated the clear proliferative lesion-promoting effects of pulmonary ligation on the induction of the expression of mRNAs related to the cell cycle, cell division and mitosis. However, the proliferative lesion-promoting effects were not strong enough to allow a shortened experimental period for the establishment of the lung bioassay model. The results also indicated the necessity to pay attention to the possibility of a recurrence of lung cancer in the residual lung after resection in humans.

Impact of older age on clinicopathological and prognostic features of colon cancer in postmenopausal women.

To clarify the clinicopathological features of colorectal cancer in older people, systematic studies considering age, sex, and the tumor locus is needed. We focused on colon cancer in postmenopausal women (<70 years, n = 68 vs. ≥70 years, n = 85), and examined the effect of age on clinicopathological features. Rates of medullary carcinoma /mucinous carcinoma were higher and pathological stages at diagnosis were less advanced in patients ≥70 years compared with <70 years. Matching pathological stages, no significant difference in disease-free interval was observed according to age; however, disease-specific survival (DSS) was poorer in patients ≥70 years than <70 years, being significantly different in stage IV cases. Regarding post-metastasis/recurrence (met/rec) cases, chemotherapy and surgery for metastasis were less frequent in those aged ≥70 years than <70 years. Post-met/rec DSS was poorer in ≥70 years, those with microsatellite instability, and those without surgery for met/rec than in each counterpart; however, post-met/rec chemotherapy exhibited no effect. Multivariate analyses revealed that an older age and no surgery for metastasis were independent predictors of disease-specific death. These findings remained after excluding stage IV cases. Older age was a potent risk factor of rapid disease-specific death after met/rec.

Clinicopathological characteristics of gastric cancer with carbohydrate antigen 19-9 expression occurring in elderly individuals: An autopsy study.

The clinicopathological significance of carbohydrate antigen 19-9 (CA19-9) in gastric cancer (GC) remains obscure. Therefore, the current study aimed to clarify the clinicopathological value of CA19-9 in GC utilizing autopsy cases. We examined the expression of CA19-9 and mucin core proteins in GC immunohistochemically, and analyzed serum CA19-9 levels and clinicopathological variables or complications. We also investigated whether fucosyltransferases 2 and 3 (FUT2/3) allelic variants influence CA19-9 expression in GC. Compared to GC cases with negative CA19-9 expression (tCA19-9-N), those with positive CA19-9 expression (tCA19-9-P) demonstrated significant differences in characteristic features such as lymph node and distant organ metastases, lymphatic and venous permeation, and higher Tumor, Node, Metastasis (TNM) stages. Moreover, compared to GC cases with low serum CA19-9 levels (sCA19-9-L), those with high serum CA19-9 levels (sCA19-9-H) were related to venous permeation, higher proportion of lymph node and distant organ metastases, and higher TNM stages. Both tCA19-9-P GC and sCA19-9-H GC cases were significantly associated with coagulation abnormalities. sCA19-9-H GC cases correlated significantly with MUC1 and MUC5AC expression. FUT2/3 genotypes were not associated with CA19-9 expression in GC. These results suggest that CA19-9 can predict the risk of lymph node and distant metastases as well as of coagulation abnormalities.

Solid-type poorly differentiated adenocarcinoma of the stomach: clinicopathological and molecular characteristics and histogenesis.

BACKGROUND: Despite predominant microsatellite instability (MSI) in intestinal-type gastric carcinomas, we found the most frequent MSI in solid-type poorly differentiated adenocarcinoma (PDA). Although this tumor is classified as PDA, it is hypothesized to possess peculiar features among PDAs. The present study aimed to clarify the clinicopathological and molecular characteristics of this tumor. METHODS: We examined the expression of p53, mismatch-repair proteins, and mucin core glycoproteins; microsatellite status; and mutations in KRAS and BRAF, as well as clinicopathological features, in 54 cases of PDA of the stomach (31 solid-type PDAs and 23 non-solid-type PDAs). RESULTS: The proportion (51.6%) of MSI in solid-type PDA was significantly higher than that in non-solid-type PDA (4.5%) (p = 0.00022). The proportion of absent expression of MLH1 (58.1%) and PMS2 (51.6%) in solid-type PDA was significantly higher than that in non-solid-type PDA (4.5 and 8%) (p < 0.0001). No differences were found in the mutations of KRAS and BRAF among PDAs. MSI-positive solid-type PDA was significantly associated with older age, female predominance, lower third location, concordant glandular component, and absent MLH1 and PMS2 expression. CONCLUSIONS: These results suggest that MSI-positive solid-type PDA has peculiar clinicopathological features and that MSI with absent MLH1 and PMS2 expression may play an important role in tumor development. In addition, from the viewpoint of histogenesis, MSI-positive solid-type PDA may originate from differentiated-type adenocarcinoma.

KRAS status is related to histological phenotype in gastric cancer: results from a large multicentre study.

BACKGROUND: Gastric cancer (GC) is histologically a very heterogeneous disease, and the temporal development of different histological phenotypes remains unclear. Recent studies in lung and ovarian cancer suggest that KRAS activation (KRASact) can influence histological phenotype. KRASact likely results from KRAS mutation (KRASmut) or KRAS amplification (KRASamp). The aim of the study was to investigate whether KRASmut and/or KRASamp are related to the histological phenotype in GC. METHODS: Digitized haematoxylin/eosin-stained slides from 1282 GC resection specimens were classified according to Japanese Gastric Cancer Association (JGCA) and the Lauren classification by at least two observers. The relationship between KRAS status, predominant histological phenotype and clinicopathological variables was assessed. RESULTS: KRASmut and KRASamp were found in 68 (5%) and 47 (7%) GCs, respectively. Within the KRASmut and KRASamp cases, the most frequent GC histological phenotype was moderately differentiated tubular 2 (tub2) type (KRASmut: n = 27, 40%; KRASamp: n = 21, 46%) or intestinal type (KRASmut: n = 41, 61%; KRASamp: n = 23, 50%). Comparing individual histological subtypes, mucinous carcinoma displayed the highest frequency of KRASmut (JGCA: n = 6, 12%, p = 0.012; Lauren: n = 6, 12%, p = 0.013), and KRASamp was more frequently found in poorly differentiated solid type (n = 12, 10%, p = 0.267) or indeterminate type (n = 12, 10%, p = 0.480) GC. 724 GCs (57%) had intratumour morphological heterogeneity. CONCLUSIONS: This is the largest GC study investigating KRAS status and histological phenotype. We identified a relationship between KRASmut and mucinous phenotype. The high level of intratumour morphological heterogeneity could reflect KRASmut heterogeneity, which may explain the failure of anti-EGFR therapy in GC.

Correction to: KRAS status is related to histological phenotype in gastric cancer: results from a large multicentre study.

In the original publication of this article, Fig. 2 was published incorrectly. The correct Fig. 2 is given in this correction.

Age-related morphological changes in the pancreas and their association with pancreatic carcinogenesis.

Age-related pathological changes in the pancreas have been unclear because they are often minor and nonspecific. However, recent studies have shown that they are closely related to various pathological conditions such as pancreatic cancer and diabetes mellitus. Knowledge of age-related changes is important to determine appropriate prevention, detection, and treatment strategies for various diseases observed in elderly patients. We present a review of the pathological age-related non-neoplastic changes in the exocrine pancreas such as pancreatic fatty replacement, lobulocentric pancreatic atrophy, pancreatic duct ectasia, and metaplasia of exocrine pancreas, as well as changes in islet cells. We have discussed common pancreatic neoplasms in elderly patients, such as pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasms (IPMNs), and pancreatic ductal adenocarcinoma (PDAC). Age-related pathological changes play a key role in pancreatic carcinogenesis via telomere dysfunction. Further studies are warranted to clarify molecular mechanisms of pancreatic carcinogenesis in elderly patients.

Expression and Roles of S100A4 in Anaplastic Cells of Canine Mammary Carcinomas.

S100A4 (metastasin), a member of the S100 protein family, was initially identified in metastatic cells and is well established as a marker of aggressive human cancer. However, expression and roles of S100A4 in canine mammary tumors have not been clarified. In this study, expression of S100A4 was examined immunohistochemically in normal, hyperplastic, and neoplastic mammary glands of dogs. In all normal and benign lesions, S100A4 was restricted to a few stromal fibroblasts and inflammatory cells. However, in 7 of 57 (12%) of the malignant tumors examined, cytoplasmic and nuclear expression of S100A4 was observed in epithelial tumor cells and stromal cells. Particularly, the frequency of S100A4-positive anaplastic carcinomas was high (4/8 cases, 50%). Next, we established a novel cell line, named NV-CML, from a S100A4-positive canine mammary carcinoma. The cultured NV-CML cells and the tumors that developed in the immunodeficient mice after subcutaneous injection of the cells maintained the immunophenotype of the original tumor, including S100A4 expression. Using this cell line, we examined the cellular functions of S100A4 using RNA interference. S100A4 expression level in NV-CML cells transfected with small interfering RNA (siRNA) targeting canine S100A4 (siS100A4) was reduced to about one-fifth of those with negative-control siRNA (siNeg). Cell proliferation in WST-8 assay and cell migration in Boyden chamber assay were significantly decreased in siS100A4-transfected cells compared with siNeg-transfected cells. These findings suggest that S100A4 may be related to progression of canine mammary carcinomas via its influence on cell growth and motility.

Abnormal immunolabelling of SMAD4 in cell block specimens to distinguish malignant and benign pancreatic cells.

BACKGROUND: Accurate diagnosis of malignant and benign pancreatic lesions can be challenging, especially with endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples that are small and/or degraded. In the present study, we determined how to best evaluate abnormal SMAD4 expression by immunohistochemical staining on cell block specimens from EUS-FNA samples. RESULTS: In surgically resected pancreas, when abnormal SMAD4 immunolabelling was evaluated as negative SMAD4 expression, the sensitivity was low (33%), but when it was evaluated as decreased SMAD4 expression, the sensitivity improved (53%). Specificity and positive predictive value were high for both evaluations. There were no false-positive cases. In cell block specimens, decreased SMAD4 expression showed 47% sensitivity and 72% specificity, while negative SMAD4 expression showed lower sensitivity (20%) and higher specificity (100%). Both evaluations in cell block specimens showed lower sensitivity and specificity compared to resected specimens. False-positive and -negative rates were higher for cell blocks than for resected specimens. CONCLUSIONS: Decreased SMAD4 immunolabelling provided improved sensitivity as compared to negative SMAD4 immunolabelling; therefore, it is important to compare SMAD4 expression in a sample to its expression in normal cells. Abnormal SMAD4 labelling showed low sensitivity and high specificity; therefore, SMAD4 staining using EUS-FNA samples might be helpful to detect malignancies that possess SMAD4 gene abnormalities.

Development and Clinical Trials of Nucleic Acid Medicines for Pancreatic Cancer Treatment.

Approximately 30% of pancreatic cancer patients harbor targetable mutations. However, there has been no therapy targeting these molecules clinically. Nucleic acid medicines show high specificity and can target RNAs. Nucleic acid medicine is expected to be the next-generation treatment next to small molecules and antibodies. There are several kinds of nucleic acid drugs, including antisense oligonucleotides, small interfering RNAs, microRNAs, aptamers, decoys, and CpG oligodeoxynucleotides. In this review, we provide an update on current research of nucleic acid-based therapies. Despite the challenging obstacles, we hope that nucleic acid drugs will have a significant impact on the treatment of pancreatic cancer. The combination of genetic diagnosis using next generation sequencing and targeted therapy may provide effective precision medicine for pancreatic cancer patients.

Relationship between pancreatic intraepithelial neoplasias, pancreatic ductal adenocarcinomas, and single nucleotide polymorphisms in autopsied elderly patients.

We comparatively analyzed serially autopsied, elderly Japanese patients (n = 2205) with pancreatic intraepithelial neoplasias (PanINs) and pancreatic ductal adenocarcinomas (PDACs) on the basis of their pancreatic lesions, clinical information, and single nucleotide polymorphisms (SNPs). The incidence of PanIN-1, -2, -3, and PDACs in these patients was 55%, 12%, 1.4%, and 2.4%, respectively. The occurrence of PanINs was associated with female sex, increasing age, and lower body mass index. We did not identify any common SNPs between PanINs and PDACs. There were no common SNPs associated with PanINs and PDACs between men and women. In previously reported pancreatic cancer-associated SNPs, rs3790844 (NR5A2) showed a significant correlation with PDAC in our cohort. Six SNPs (rs7016880, rs10096633, rs10503669, rs12678919, rs17482753, rs328) that were correlated with blood lipid levels were associated with the risk for PDACs. Our data suggest that different clinicopathological characteristics and predispositions may affect pancreatic carcinogenesis in elderly Japanese patients.

Reduced expression of the H19 long non-coding RNA inhibits pancreatic cancer metastasis.

H19 is an oncofetal RNA expressed in the developing embryo as well as in bladder, breast, gastric, pancreatic, hepatocellular, and prostate cancers. Recent studies have shown that H19 enhances cancer invasion and metastasis; however, its roles in cancer remain controversial. In the current study, H19 exhibited the second largest increase (82.4-fold) and represented the only non-protein coding gene among 11 genes identified that were elevated over 10-fold in lung-metastasis-derived pancreatic cancer cells compared with their parental cells using a mouse metastatic model. Subsequently, we further clarified the roles of H19 in pancreatic cancer growth and metastasis using in vitro and in vivo techniques. In situ hybridization showed that H19 was detected in 23 of 139 invasive ductal carcinomas (17%), and that H19 expression positively correlated with higher histological grades (P < 0.0001). Overexpression of H19 in PANC-1 pancreatic cancer cells induced higher motilities, whereas H19 inhibition using shRNA and siRNA showed opposite results; however, cell growth rates were not impacted. Intravenous injection of H19 shRNA vector-transfected PANC-1 cells yielded marked inhibition of metastasis in the liver and lungs of immunodeficient mice. These findings suggest that H19 has important roles in pancreatic cancer metastasis, and that inhibition of H19 represents a novel candidate for pancreatic cancer therapy.