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.

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.

Vasoactive intestinal peptide blockade suppresses tumor growth by regulating macrophage polarization and function in CT26 tumor-bearing mice.

Macrophages are a major population of immune cells in solid cancers, especially colorectal cancers. Tumor-associated macrophages (TAMs) are commonly divided into M1-like (tumor suppression) and M2-like (tumor promotion) phenotypes. Vasoactive intestinal peptide (VIP) is an immunoregulatory neuropeptide with a potent anti-inflammatory function. Inhibition of VIP signaling has been shown to increase CD8+ T cell proliferation and function in viral infection and lymphoma. However, the role of VIP in macrophage polarization and function in solid tumors remains unknown. Here, we demonstrated that conditioned medium from CT26 (CT26-CM) cells enhanced M2-related marker and VIP receptor (VPAC) gene expression in RAW264.7 macrophages. VIP hybrid, a VIP antagonist, enhanced M1-related genes but reduced Mrc1 gene expression and increased phagocytic ability in CT26-CM-treated RAW264.7 cells. In immunodeficient SCID mice, VIP antagonist alone or in combination with anti-PD-1 antibody attenuated CT26 tumor growth compared with the control. Analysis of tumor-infiltrating leukocytes found that VIP antagonist increased M1/M2 ratios and macrophage phagocytosis of CT26-GFP cells. Furthermore, Vipr2 gene silencing or VPAC2 activation affected the polarization of CT26-CM-treated RAW264.7 cells. In conclusion, the inhibition of VIP signaling enhanced M1 macrophage polarization and macrophage phagocytic function, resulting in tumor regression in a CT26 colon cancer model.

Association of longer telomere length in cancer cells and cancer-associated fibroblasts with worse prognosis.

BACKGROUND: Telomere dysfunction has been reported to be directly involved in carcinogenesis owing to chromosomal instability and immortalization; however, the clinicopathological significance of telomeres remains controversial. We have shown that telomere shortening occurs in normal-appearing duct cells at initiation and then continues during the progression of pancreatic cancer. In this study, we determined the clinicopathological and prognostic value of telomere length (TL) in cancer progression. METHODS: TL in both cancer cells and cancer-associated fibroblasts (CAFs) was analyzed by high-throughput quantitative fluorescence in situ hybridization using a previously reported cohort comprising 1434 cases of adenocarcinoma (ADC), squamous cell carcinoma (SCC), adenosquamous carcinoma, hepatocellular carcinoma, and renal cell carcinoma (RCC), which are known cancers with a statistically significantly low incidence of alternative lengthening of telomeres. Cases were divided into 2 groups as follows: longer and shorter telomeres, according to the median TL of cancer cells and CAFs. The statistical significance of TL in cancer cells and CAFs on clinicopathological characteristics and prognosis was analyzed. RESULTS: There was a close association between TL in cancer cells and CAFs. Longer telomeres in cancer cells and CAFs were associated with aggressive features such as advanced stage, high mitosis score and nuclear score, poorly differentiated cancer, and desmoplastic stroma in ADC. Furthermore, a longer TL was an independent prognostic factor for ADC, SCC, and RCC. CONCLUSIONS: Longer telomeres are associated with worse prognosis in ADC, SCC, and RCC. Thus, TL is a novel biomarker for the diagnosis of aggressive cancers with poor prognoses.

STNM01, the RNA oligonucleotide targeting carbohydrate sulfotransferase 15, as second-line therapy for chemotherapy-refractory patients with unresectable pancreatic cancer: An open label, phase I/IIa trial.

Background: The impact of stroma-targeting therapy on tumor immune suppression is largely unexplored. An RNA oligonucleotide, STNM01, has been shown to repress carbohydrate sulfotransferase 15 (CHST15) responsible for tumor proteoglycan synthesis and matrix remodeling. This phase I/IIa study aimed to evaluate the safety and efficacy of STNM01 in patients with unresectable pancreatic ductal adenocarcinoma (PDAC). Methods: This was an open-label, dose-escalation study of STNM01 as second-line therapy in gemcitabine plus nab-paclitaxel-refractory PDAC. A cycle comprised three 2-weekly endoscopic ultrasound-guided locoregional injections of STNM01 at doses of 250, 1,000, 2,500, or 10,000 nM in combination with S-1 (80-120 mg twice a day for 14 days every 3 weeks). The primary outcome was the incidence of dose-liming toxicity (DLT). The secondary outcomes included overall survival (OS), tumor response, changes in tumor microenvironment on immunohistopathology, and safety (jRCT2031190055). Findings: A total of 22 patients were enrolled, and 3 cycles were repeated at maximum; no DLT was observed. The median OS was 7.8 months. The disease control rate was 77.3%; 1 patient showed complete disappearance of visible lesions in the pancreas and tumor-draining lymph nodes. Higher tumoral CHST15 expression was associated with poor CD3+ and CD8+ T cell infiltration at baseline. STNM01 led to a significant reduction in CHST15, and increased tumor-infiltrating CD3+ and CD8+ T cells in combination with S-1 at the end of cycle 1. Higher fold increase in CD3+ T cells correlated with longer OS. There were 8 grade 3 adverse events. Interpretation: Locoregional injection of STNM01 was well tolerated in patients with unresectable PDAC as combined second-line therapy. It prolonged survival by enhancing T cell infiltration in tumor microenvironment. Funding: The present study was supported by the Japan Agency for Medical Research and Development (AMED).

Telomere Attrition in Intraductal Papillary Mucinous Neoplasms of the Pancreas Associated With Carcinogenesis and Aging.

OBJECTIVES: It is challenging to preoperatively distinguish malignant and benign forms of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. The aims of this study were to investigate whether telomere length is associated with pathological grade of IPMNs and age and to clarify the utility of telomere length as a marker to identify malignant IPMNs. METHODS: Pancreas tissue was obtained from 28 patients after resection. We measured the telomere lengths of tumor cells in IPMNs and normal duct cells by quantitative fluorescence in situ hybridization. The association of normalized telomere-centromere ratio (NTCR) to pathological grade of IPMNs and age were determined. RESULTS: The NTCR showed a gradual decrease with increasing pathological grade of IPMNs. The NTCR in intermediate- and high-grade dysplasia and adenocarcinoma lesions was significantly shorter than in normal pancreatic ducts (P < 0.05). In multivariate analysis, telomere length was most associated with carcinogenesis. When the cutoff value of NTCR was set to 0.74, the sensitivity for detection of high-grade dysplasia and adenocarcinoma was 82.8%, with a specificity of 87.5%. CONCLUSIONS: Telomere shortening occurs with carcinogenesis and aging. A significant reduction of telomere length in IPMNs may be useful for surgical decision making.

Telomere length was associated with grade and pathological features of meningioma.

Telomeres are tandem repeats of the TTAGGG sequence at chromosomal ends and afford protection against chromosomal instability. To investigate the contribution of telomere dysfunction in meningiomas, here we estimate the associations between telomere length, tumor grade, and proliferation index in a series of 14 archived samples, using quantitative-fluorescence in situ hybridization, Ki67 immunostaining, and pathological analysis. The number of mitoses per 10 high-power fields (HPF) and Ki67 index was higher in grade III cases than in grade I or grade II cases. Telomere length was negatively associated with both the number of mitoses/10HPF and Ki67 index. Meningioma cases with atypical mitosis, a morphological marker of chromosomal instability, exhibited shortened telomeres. Among telomere-shortened meningioma cases, 40% were grade I, 20% were grade II, and 100% were grade III. In grade I or II meningiomas, shortened telomeres lacked high proliferation activity and atypical mitosis. In conclusion, telomere shortening might be pivotal in the development of high-grade meningioma. Analysis of telomere length might be a selective marker for meningiomas with high-grade malignant potential.

Lactulose Modulates the Structure of Gut Microbiota and Alleviates Colitis-Associated Tumorigenesis.

Lactulose, a galactose-fructose disaccharide, is made from the milk sugar lactose by heating or isomerization processes. Lactulose is proposed to modulate gut microbiota and thus expected to be beneficial in treating inflammatory bowel disease. In the present study, we investigated the therapeutic effect of lactulose on gastrointestinal inflammation and inflammation-related tumorigenesis in a mouse model of colorectal cancer as well as its effect on gut microbiota composition. Azoxymethane (AOM)/dextran sulfate sodium (DSS) model was used in this study. Lactulose treatment was performed by feeding 2% lactulose for 14 weeks. Stool samples collected at 4 time points were used for metagenomic analysis of the microbiota. Pathological analysis was performed 21 weeks after AOM injection. AOM/DSS increased the macrophage counts, inflammatory cytokine expression, colorectal tumorigenesis, and imbalance in gut microbiota composition, as evidenced by increased pathogen abundance (e.g., Escherichia and Clostridium). Lactulose significantly inhibited the inflammatory events, and ameliorated inflammation and tumorigenesis. The composition of the intestinal microbiota was also restored upon lactulose treatment, and lactulose reduced pathogen abundance and increased the abundance of Muribaculum and Lachnospiraceae. Meanwhile, the pathways related to Crohn's disease were downregulated after lactulose treatment. Our findings suggest that lactulose restores the structure and composition of the intestinal microbiota, mitigates inflammation, and suppresses inflammatory tumorigenesis.

Intralobular distribution of ovarian-like stroma in pancreatic mucinous cystic neoplasms: a discussion on its tumorigenesis.

Pancreatic mucinous cystic neoplasm (MCN) has two histological components: tumor epithelia and ovarian-like stroma (OLS). To examine the progression and changes in pancreatic MCNs, we analyzed the distribution, amount, immunohistochemical phenotype, presence of theca cells of OLS, and tumor epithelium in 45 surgically resected MCN cases, comparing them with tumor sizes. The OLS data of female MCN cases were also compared between those who were ≤ 51 years old and those > 51 years old to see the effect of menopause on MCN histology. Non-mucinous type epithelium was present in all low-grade MCNs, but its ratio decreased with tumor size (p < 0.001), suggesting that epithelial mucinous changes are a progression phenomenon. The intralobular distribution of OLS was observed in 28.8% of MCN cases and was related to smaller tumor size (p < 0.0001), suggesting intralobular involvement of early MCNs. The nuclear expression of ß-catenin and the cytoplasmic expression of α-smooth muscle actin (SMA) was observed in almost all OLS. OLS tended to be lesser among female cases aged > 51 years than those ≤ 51 years old, however it did not reach statistical significance. This is the first study to show the intralobular distribution of OLS.

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 concentration and estrogen receptor-ß expression in postmenopausal colon cancer considering patient/tumor background.

PURPOSE: A large number of studies have suggested an inhibitory role of estrogens against colorectal cancer (CRC), but persistent controversy exists. CRC characteristics are affected by sex, age, and tumor locus, suggesting the need for a systematic study considering these factors. The purpose of this study was to verify the difference in the pathobiological role of estrogens in CRC according to patient/tumor backgrounds. METHODS: Surgical specimens from 116 postmenopausal women (≥ 70 years/o, n = 74; < 70 years/o, n = 42) were studied. Estrogen receptor-ß (ER-ß), the main ER in the colorectal epithelium, was immunohistochemically examined. The concentrations of estradiol (E2) and estrone (E1) were examined by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These factors were compared according to the tissue type (cancerous or non-cancerous), patients' age, tumor backgrounds (locus, histology, pathological stage, status of mismatch repair protein = MMR), and clinical outcome. RESULTS: ER-ß-positivity, higher E2 concentration, deficient-MMR, and medullary/mucinous histology (Med/Muc) were closely related to right-sided tumors in women who were aged ≥ 70 years /o (R-Ca ≥ 70) and also closely related to each other. ER-ß reduction compared with non-cancerous counterparts was observed only in left-sided tumors of patients < 70 years /o (L-Ca < 70), non-Med/Muc, or proficient-MMR tumors. CONCLUSION: The present results suggest that estrogens do not suppress, but rather promote, R-Ca ≥ 70, Med/Muc, or deficient-MMR tumors, whereas estrogens suppress L-Ca < 70, non-Med/Muc, or proficient-MMR tumors, confirming the difference in pathobiological role of estrogens in postmenopausal colon cancer according to the patients' age and tumor background. This may at least partly explain the controversy regarding the association between estrogens and CRC.

Telomerase Reverse Transcriptase Promoter Mutations in Human Hepatobiliary, Pancreatic and Gastrointestinal Cancer Cell Lines.

BACKGROUND/AIM: The promoter region of the telomerase reverse transcriptase (TERT) gene is a regulatory element capable of affecting TERT expression, telomerase activity, and telomerase length. Mutations within the TERT promoter region are the most common mutations in many cancers. In this study, we characterized the TERT promoter mutation status in hepatobiliary, pancreatic, and gastrointestinal cancer cell lines. MATERIALS AND METHODS: TERT promoter mutation status was assessed by digital PCR in 12 liver cancer, 5 cholangiocarcinoma (CCA), 12 pancreatic cancer, 17 gastrointestinal cancer, and 3 healthy control cell lines. RESULTS: The C228T promoter mutation was detected in 9 liver cancer lines, and the C250T TERT mutation was detected in 1 oesophageal squamous cell carcinoma line. CONCLUSION: The C228T promoter mutation is specific to liver cancer cell lines among various gastrointestinal cancer cell lines. These data will contribute to future research on the tumorigenic mechanisms and clinical use of digital PCR to detect mutations.

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.

Pathologic Examination of Pancreatic Specimens Resected for Treated Pancreatic Ductal Adenocarcinoma: Recommendations From the Pancreatobiliary Pathology Society.

Currently, there are no internationally accepted consensus guidelines for pathologic evaluation of posttherapy pancreatectomy specimens. The Neoadjuvant Therapy Working Group of Pancreatobiliary Pathology Society was formed in 2018 to review grossing protocols, literature, and major issues and to develop recommendations for pathologic evaluation of posttherapy pancreatectomy specimens. The working group generated the following recommendations: (1) Systematic and standardized grossing and sampling protocols should be adopted for pancreatectomy specimens for treated pancreatic ductal adenocarcinoma (PDAC). (2) Consecutive mapping sections along the largest gross tumor dimension are recommended to validate tumor size by histology as required by the College of American Pathologists (CAP) cancer protocol. (3) Tumor size of treated PDACs should be measured microscopically as the largest dimension of tumor outer limits that is bound by viable tumor cells, including intervening stroma. (4) The MD Anderson grading system for tumor response has a better correlation with prognosis and better interobserver concordance among pathologists than does the CAP system. (5) A case should not be classified as a complete response unless the entire pancreas, peripancreatic tissues, ampulla of Vater, common bile duct, and duodenum adjacent to the pancreas are submitted for microscopic examination. (6) Future studies on tumor response of lymph node metastases, molecular and/or immunohistochemical markers, as well as application of artificial intelligence in grading tumor response of treated PDAC are needed. In summary, systematic, standardized pathologic evaluation, accurate tumor size measurement, and reproducible tumor response grading to neoadjuvant therapy are needed for optimal patient care. The criteria and discussions provided here may provide guidance towards these goals.

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.

A Case of Adult Pancreatoblastoma With Novel APC Mutation and Genetic Heterogeneity.

BACKGROUND: Pancreatoblastoma is a rare malignant epithelial neoplasm of the pancreas that mainly occurs in children and involves abnormalities in the WNT/ß-catenin pathway, such as CTNNB1 mutation. However, the molecular abnormalities in adult pancreatoblastoma are not well known. CASE PRESENTATION: An elderly man, who underwent elective distal pancreatectomy and splenectomy, was referred to our hospital with a mass in the tail of the pancreas. Histologically, the lesion revealed proliferation of clear, basophilic, and cartilaginous tumor cells with lymphatic metastasis. Each of the morphologically distinct tumor components showed different immunohistochemical patterns, indicating heterogeneous differentiation, including epithelial (both acinar and ductal), mesenchymal, and neuroendocrine differentiation. All tumor components showed nuclear expression of ß-catenin and cyclin D1. Per next-generation sequencing (NGS), the clear and basophilic tumor cells shared mutations in APC, GRM8, LAMP1, and AKA9. Among the mutations, APC, c.1816_1817insA showed the highest frequency in both cell types, indicating that APC mutation was a driver mutation of the tumor. A diagnosis of PB was rendered. SUMMARY: In conclusion, the clear and basophilic cells of the tumor were supposedly derived from the same clone and subsequently acquired additional mutations. This is the first report of clonal evolution in pancreatoblastoma.

Relationship between Lung Carcinogenesis and Chronic Inflammation in Rodents.

Lung cancer remains the leading cause of cancer-related deaths, with an estimated 1.76 million deaths reported in 2018. Numerous studies have focused on the prevention and treatment of lung cancer using rodent models. Various chemicals, including tobacco-derived agents induce lung cancer and pre-cancerous lesions in rodents. In recent years, transgenic engineered rodents, in particular, those generated with a focus on the well-known gene mutations in human lung cancer (KRAS, EGFR, and p53 mutations) have been widely studied. Animal studies have revealed that chronic inflammation significantly enhances lung carcinogenesis, and inhibition of inflammation suppresses cancer progression. Moreover, the reduction in tumor size by suppression of inflammation in animal experiments suggests that chronic inflammation influences the promotion of tumorigenesis. Here, we review rodent lung tumor models induced by various chemical carcinogens, including tobacco-related carcinogens, and transgenics, and discuss the roles of chronic inflammation in lung carcinogenesis.

Carcinogenesis of Triple-Negative Breast Cancer and Sex Steroid Hormones.

Triple-negative breast cancer (TNBC) lacks an effective treatment target and is usually associated with a poor clinical outcome; however, hormone unresponsiveness, which is the most important biological characteristic of TNBC, only means the lack of nuclear estrogenic signaling through the classical estrogen receptor (ER), ER-α. Several sex steroid receptors other than ER-α: androgen receptor (AR), second ER, ER-ß, and non-nuclear receptors represented by G-protein-coupled estrogen receptor (GPER), are frequently expressed in TNBC and their biological and clinical importance has been suggested by a large number of studies. Despite the structural similarity between each sex steroid hormone (androgens and estrogens) or each receptor (AR and ER-ß), and similarity in the signaling mechanisms of these hormones, most studies or reviews focused on one of these receptors, and rarely reviewed them in a comprehensive way. Considering the coexistence of these hormones and their receptors in TNBC in a clinical setting, a comprehensive viewpoint would be important to correctly understand the association between the carcinogenic mechanism or pathobiology of TNBC and sex steroid hormones. In this review, the carcinogenic or pathobiological role of sex steroid hormones in TNBC is considered, focusing on the common and divergent features of the action of these hormones.

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.