Immunohistochemical Expression of Glutathione Peroxidase-2 (Gpx-2) and Its Clinical Relevance in Colon Adenocarcinoma Patients.

Glutathione peroxidase 2 (Gpx-2) is a selenoenzyme with antioxidant capabilities that may play a role in cancer development. Hence, we investigated the immunohistochemical expression of Gpx-2 protein in colon adenocarcinoma samples derived from patients with colon adenocarcinoma who did not receive any form of treatment prior to the surgical procedure. The associations between the immunohistochemical expression of Gpx-2 and clinical parameters were analysed using the Chi2 test and Fisher's exact test. A Kaplan-Meier analysis and the log-rank test were used to verify the relationship between the intensity of Gpx-2 expression and the 5-year survival rate of patients. In total, 101 (80.80%) samples had strong Gpx-2 protein expression and 24 (19.20%) samples were characterized with low expression. The high expression of Gpx-2 was correlated with the histological grade of the tumour (p < 0.001), PCNA immunohistochemical expression (p < 0.001), depth of invasion (p = 0.001) and angioinvasion (p < 0.001). We can conclude that high expression of Gpx-2 is correlated with reduced survival of colon adenocarcinoma patients (log-rank, p < 0.001).

Loss of ATP5A1 enhances proliferation and predicts poor prognosis of colon adenocarcinoma.

BACKGROUND: ATP Synthase F1 Subunit Alpha (ATP5F1A), also named as ATP5A1, is a subunit of mitochondrial ATP synthase. Dysregulated expression of ATP5A1 has been reported in several malignancies, nevertheless it showed either oncogenic or tumor-suppressing roles in different cancer types. Here we aimed to initially investigate the expression and role of ATP5A1 in colon adenocarcinoma. METHODS: We firstly evaluated the transcription and mRNA levels of ATP5A1 using data from The Cancer Genome Atlas (TCGA). Besides, we tested its mRNA and protein expression in our enrolled retrospective cohort (n = 115). Univariate and multivariate analyzes were conducted to assess its prognostic value. Cellular experiments and xenografts in mice model were performed to validate the role of ATP5A1 in colon cancer. RESULTS: ATP5A1 showed a significant lower level in colon adenocarcinoma than in adjacent nontumorous tissue. Advanced tumor stage was characterized with lower ATP5A1 level. Lower ATP5A1 was associated with poor prognosis in both TCGA dataset (P = 0.041) and our cohort (P = 0.001). Furthermore, Cox regression analysis demonstrated that ATP5A1 was a novel independent prognostic factor for colon cancer patients (HR=0.43, P = 0.018). Finally, cellular and xenografts data confirmed that overexpressing ATP5A1 can remarkably attenuate colon cancer growth. CONCLUSION: Low expression of ATP5A1 may be a potential molecular marker for poor prognosis in colon cancer. DATA AVAILABILITY: Data will be available upon request.

Pepsinogen I- and H+/K+-ATPase-immunohistochemical Positivity in Endoscopically Resected Early Gastric Neoplasia.

Gastric adenocarcinoma of the fundic gland type (GAFG) has been recently classified by the World Health Organization (WHO), however, clinicopathologic features of pepsinogen I- or H+/K+-ATPase-positive gastric tumors remain unclear. Therefore, this study evaluates the frequency and clinicopathologic features of those tumors, using a tissue microarray block to identify pepsinogen I- or H+/K+-ATPase-positive tumors from 810 endoscopically resected, early gastric epithelial tumors. The frequency of pepsinogen I-positive lesions was 2.1%, and that of H+/K+-ATPase-positive lesions was 2.0%. Pepsinogen I- or H+/K+-ATPase positivity was not observed in undifferentiated-type tumors, while gastric tumors with morphologic similarity to fundic glands were positive for pepsinogen I- or H+/K+-ATPase. We divided pepsinogen I- or H+/K+-ATPase-positive gastric tumors into group A, with fundic gland-like structure, or group B, without fundic gland-like structure. The frequency of group A was 1.6%: 46.2% were positive only for pepsinogen I and 53.8% for H+/K+-ATPase and pepsinogen I. The frequency of group B was 1.5%: 25% were positive only for pepsinogen I, 8.3% for H+/K+-ATPase and pepsinogen I, and 66.7% only for H+/K+-ATPase. The 2 tumor groups differed in location and endoscopic features. Hematoxylin and eosin staining showed that group B had more exposed tumors to the surface, larger nuclei, and more background atrophy than group A. Immunostaining showed significantly higher positivity rates for MUC5AC, CD10, CDX2, and p53 expression, and a higher Ki-67 labeling score. Our results provide novel insights into the pathology of early gastric tumors with histologic or immunohistochemical evidence of fundic gland differentiation.

Knockdown of the inducible nitric oxide synthase (NOS2) splicing variant S3 promotes autophagic cell death from nitrosative stress in SW480 human colon cancer cells.

Low levels of nitric oxide (NO) produced by constitutively expressed inducible NO synthase (NOS2) in tumor cells may be an important factor in their development. NOS2 expression is associated with high mortality rates for various cancers. Alternative splicing of NOS2 down-regulates its enzymatic activity, resulting in decreased intracellular NO concentrations. Specific probes to detect alternative splicing of NOS2 were used in two isogenic human colon cancer cell lines derived either from the primary tumor (SW480) or from a lymph node metastasis (SW620). Splicing variant of NOS2 S3, lacking exons 9, 10, and 11, was overexpressed in SW480 cells. NOS2 S3 was silenced in SW480 cells. Flow-cytometry analysis was used to estimate the intracellular NO levels and to analyze the cell cycle of the studied cell lines. Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine apoptosis and autophagy markers. SW480 and SW620 cells expressed NOS2 S3. Overexpression of the NOS2 S3 in SW480 cells downregulated intracellular NO levels. SW480 cells with knocked down NOS2 S3 (referred to as S3C9 cells) had higher intracellular levels of NO compared to the wild-type SW480 cells under serum restriction. Higher NO levels resulted in the loss of viability of S3C9 cells, which was associated with autophagy. Induction of autophagy by elevated intracellular NO levels in S3C9 cells under serum restriction, suggests that autophagy operates as a cytotoxic response to nitrosative stress. The expression of NOS2 S3 plays an important role in regulating intracellular NO production and maintaining viability in SW480 cells under serum restriction. These findings may prove significant in the design of NOS2/NO-based therapies for colon cancer.

Carbonic Anhydrases II and IX in Non-ampullary Duodenal Adenomas and Adenocarcinoma.

Non-ampullary duodenal adenocarcinoma (DAC) is a rare malignancy. Little information is available concerning the histopathological prognostic factors associated with DAC. Carbonic anhydrases (CAs) are metalloenzymes catalyzing the universal reaction of CO2 hydration. Isozymes CAII, CAIX, and CAXII are associated with prognosis in various cancers. Our aim was to analyze the immunohistochemical expressions of CAII, CAIX, and CAXII in normal duodenal epithelium, duodenal adenomas, and adenocarcinoma and their associations with clinicopathological variables and survival. Our retrospective study included all 27 DACs treated in Oulu University Hospital during years 2000-2020. For comparison, samples of 42 non-ampullary adenomas were collected. CAII expression was low in duodenal adenomas and adenocarcinoma. CAIX expression in adenomas and adenocarcinoma was comparable with the high expression of normal duodenal crypts. Expression patterns in carcinomas were largely not related to clinicopathological features. However, low expression of CAII associated with poorer differentiation of the tumor (p=0.049) and low expression of CAIX showed a trend for association with nodal spread, although statistical significance was not reached (p=0.091). CAII and CAIX lost their epithelial polarization and staining intensity in adenomas. CAXII expression was not detected in the studied samples. CAs were not associated with survival. The prognostic value of CAII and CAIX downregulation should be further investigated. Both isozymes may serve as biomarkers of epithelial dysplasia in the duodenum.

Complex Alterations of Fatty Acid Metabolism and Phospholipidome Uncovered in Isolated Colon Cancer Epithelial Cells.

The development of colon cancer, one of the most common malignancies, is accompanied with numerous lipid alterations. However, analyses of whole tumor samples may not always provide an accurate description of specific changes occurring directly in tumor epithelial cells. Here, we analyzed in detail the phospholipid (PL), lysophospholipid (lysoPL), and fatty acid (FA) profiles of purified EpCAM+ cells, isolated from tumor and adjacent non-tumor tissues of colon cancer patients. We found that a number of FAs increased significantly in isolated tumor cells, which also included a number of long polyunsaturated FAs. Higher levels of FAs were associated with increased expression of FA synthesis genes, as well as with altered expression of enzymes involved in FA elongation and desaturation, including particularly fatty acid synthase, stearoyl-CoA desaturase, fatty acid desaturase 2 and ELOVL5 fatty acid elongase 5 We identified significant changes in ratios of specific lysoPLs and corresponding PLs. A number of lysophosphatidylcholine and lysophosphatidylethanolamine species, containing long-chain and very-long chain FAs, often with high numbers of double bonds, were significantly upregulated in tumor cells. Increased de novo synthesis of very long-chain FAs, or, altered uptake or incorporation of these FAs into specific lysoPLs in tumor cells, may thus contribute to reprogramming of cellular phospholipidome and membrane alterations observed in colon cancer.

Functional inhibition of lactate dehydrogenase suppresses pancreatic adenocarcinoma progression.

BACKGROUND: Pancreatic adenocarcinoma (PAAD) a highly lethal malignancy. The current use of clinical parameters may not accurately predict the clinical outcome, which further renders the unsatisfactory therapeutic outcome. METHODS: In this study, we retrospectively analyzed the clinical-pathological characteristics and prognosis of 253 PAAD patients. Univariate, multivariate, and Kaplan-Meier survival analyses were conducted to assess risk factors and clinical outcomes. For functional study, we performed bidirectional genetic manipulation of lactate dehydrogenase A (LDHA) in PAAD cell lines to measure PAAD progression by both in vitro and in vivo assays. RESULTS: LDHA is particularly overexpressed in PAAD tissues and elevated serum LDHA-transcribed isoenzymes-5 (LDH-5) was associated with poorer patients' clinical outcomes. Genetic overexpression of LDHA promoted the proliferation and invasion in vitro, and tumor growth and metastasis in vivo in murine PAAD orthotopic models, while knockdown of LDHA exhibited opposite effects. LDHA-induced L-lactate production was responsible for the LDHA-facilitated PAAD progression. Mechanistically, LDHA overexpression reduced the phosphorylation of metabolic regulator AMPK and promoted the downstream mTOR phosphorylation in PAAD cells. Inhibition of mTOR repressed the LDHA-induced proliferation and invasion. A natural product berberine was selected as functional inhibitor of LDHA, which reduced activity and expression of the protein in PAAD cells. Berberine inhibited PAAD cells proliferation and invasion in vitro, and suppressed tumor progression in vivo. The restoration of LDHA attenuated the suppressive effect of berberine on PAAD. CONCLUSIONS: Our findings suggest that LDHA may be a novel biomarker and potential therapeutic target of human PAAD.

High expression of FBP1 and LDHB in fibroadenomas and invasive breast cancers.

BACKGROUND: The role of gluconeogenesis in cancer cells as the reverse pathway for glycolysis is not well known. Several studies of gluconeogenesis in cancer cells still show conflicting results. Expression of key enzymes such as FBP1 and LDHB in cancer tissues may explain the role of gluconeogenesis in tumor development. OBJECTIVE: This study aimed to analyze the expression of FBP1 and LDHB in fibroadenomas and invasive cancers of the breast. METHODS: The immunohistochemical staining technique was used to show the expression of FBP1 and LDHB in formalin-fixed, paraffin-embedded blocks of 32 fibroadenomas and 31 invasive breast cancer samples. RESULTS: FBP1 was expressed by the majority of fibroadenoma (68.7%) and invasive breast cancer (71%) samples. LDHB expression in fibroadenomas was significantly higher than in invasive breast cancers (P = 0.029). The expression of these two enzymes was found in invasive, lobular, and tubular breast carcinoma, and at well, moderately, and poorly differentiated breast malignancy. CONCLUSIONS: High expression of FBP1 and LDHB was found in fibroadenomas and invasive breast cancers. A higher level of LDHB expression was observed in fibroadenomas. These results may indicate the enzymes' role in the pathogenesis of both breast diseases.

NADK is activated by oncogenic signaling to sustain pancreatic ductal adenocarcinoma.

Metabolic adaptations and the signaling events that control them promote the survival of pancreatic ductal adenocarcinoma (PDAC) at the fibrotic tumor site, overcoming stresses associated with nutrient and oxygen deprivation. Recently, rewiring of NADPH production has been shown to play a key role in this process. NADPH is recycled through reduction of NADP+ by several enzymatic systems in cells. However, de novo NADP+ is synthesized only through one known enzymatic reaction, catalyzed by NAD+ kinase (NADK). In this study, we show that oncogenic KRAS promotes protein kinase C (PKC)-mediated NADK phosphorylation, leading to its hyperactivation, thus sustaining both NADP+ and NADPH levels in PDAC cells. Together, our data show that increased NADK activity is an important adaptation driven by oncogenic signaling. Our findings indicate that NADK could serve as a much-needed therapeutic target for PDAC.

Specific Pyruvate Kinase M2 Inhibitor, Compound 3K, Induces Autophagic Cell Death through Disruption of the Glycolysis Pathway in Ovarian Cancer Cells.

Ovarian cancer is a common cause of death among gynecological cancers. Although ovarian cancer initially responds to chemotherapy, frequent recurrence in patients remains a therapeutic challenge. Pyruvate kinase M2 (PKM2) plays a pivotal role in regulating cancer cell survival. However, its therapeutic role remains unclear. Here, we investigated the anticancer effects of compound 3K, a specific PKM2 inhibitor, on the regulation of autophagic and apoptotic pathways in SK-OV-3 (PKM2-overexpressing human ovarian adenocarcinoma cell line). The anticancer effect of compound 3K was examined using MTT and colony formation assays in SK-OV-3 cells. PKM2 expression was positively correlated with the severity of the tumor, and expression of pro-apoptotic proteins increased in SK-OV-3 cells following compound 3K treatment. Compound 3K induced AMPK activation, which was accompanied by mTOR inhibition. Additionally, this compound inhibited glycolysis, resulting in reduced proliferation of SK-OV-3 cells. Compound 3K treatment suppressed tumor progression in an in vivo xenograft model. Our findings suggest that the inhibition of PKM2 by compound 3K affected the Warburg effect and induced autophagic cell death. Therefore, use of specific PKM2 inhibitors to block the glycolytic pathway and target cancer cell metabolism represents a promising therapeutic approach for treating PKM2-overexpressing ovarian cancer.

Peroxiredoxin V Silencing Elevates Susceptibility to Doxorubicin-induced Cell Apoptosis via ROS-dependent Mitochondrial Dysfunction in AGS Gastric Cancer Cells.

BACKGROUND/AIM: Peroxiredoxin V (Prx V) plays crucial roles in cellular apoptosis and proliferation in various cancer cells by regulating the cellular reactive oxygen species (ROS) levels. MATERIALS AND METHODS: Here, we examined the possible regulatory effects of Prx V on doxorubicin (DOX)-induced cellular apoptosis and its mechanisms in the human gastric adenocarcinoma cell line (AGS cells). RESULTS: Our findings suggest that Prx V knockdown may significantly increase the DOX-induced apoptosis by aggravating intracellular ROS accumulation. We also found that DOX-induced mitochondrial ROS levels and membrane permeability were significantly higher in short hairpin Prx V cells than in mock cells, and these phenomena were dramatically reversed by ROS scavenger treatment. Prx V knockdown also significantly upregulated the cleaved caspase 9, 3, and B-cell lymphoma 2 (Bcl2)-associated agonist of cell death/Bcl2 protein expression levels, suggesting that Prx V knockdown activates mitochondria-dependent apoptotic signaling pathways. CONCLUSION: Taken together, this study suggests that Prx V may be a strong molecular target for gastric cancer (GC) chemotherapy, and further elucidates the role of Prx V in oxidative stress-induced cell apoptosis.

GSK-3ß Can Regulate the Sensitivity of MIA-PaCa-2 Pancreatic and MCF-7 Breast Cancer Cells to Chemotherapeutic Drugs, Targeted Therapeutics and Nutraceuticals.

Glycogen synthase kinase-3 (GSK-3) is a regulator of signaling pathways. KRas is frequently mutated in pancreatic cancers. The growth of certain pancreatic cancers is KRas-dependent and can be suppressed by GSK-3 inhibitors, documenting a link between KRas and GSK-3. To further elucidate the roles of GSK-3ß in drug-resistance, we transfected KRas-dependent MIA-PaCa-2 pancreatic cells with wild-type (WT) and kinase-dead (KD) forms of GSK-3ß. Transfection of MIA-PaCa-2 cells with WT-GSK-3ß increased their resistance to various chemotherapeutic drugs and certain small molecule inhibitors. Transfection of cells with KD-GSK-3ß often increased therapeutic sensitivity. An exception was observed with cells transfected with WT-GSK-3ß and sensitivity to the BCL2/BCLXL ABT737 inhibitor. WT-GSK-3ß reduced glycolytic capacity of the cells but did not affect the basal glycolysis and mitochondrial respiration. KD-GSK-3ß decreased both basal glycolysis and glycolytic capacity and reduced mitochondrial respiration in MIA-PaCa-2 cells. As a comparison, the effects of GSK-3 on MCF-7 breast cancer cells, which have mutant PIK3CA, were examined. KD-GSK-3ß increased the resistance of MCF-7 cells to chemotherapeutic drugs and certain signal transduction inhibitors. Thus, altering the levels of GSK-3ß can have dramatic effects on sensitivity to drugs and signal transduction inhibitors which may be influenced by the background of the tumor.

Analyzing the Role of Proteases in Breast Cancer Progression and Metastasis Using Primary Cells from Transgenic Oncomice.

It is becoming increasingly evident that progression and metastasis of solid cancers is driven by the interaction of oncogene-transformed cancer cells and non-malignant host cells in the tumor stroma. In this process, the immune system contributes a complex set of highly important pro- and antitumor effects, which are not readily recapitulated by commonly used xenograft cancer models in immunodeficient mice.Therefore, we provide protocols for isolation of primary tumor cells from the MMTV-PymT mouse model for metastasizing breast cancer and their resubmission to congenic immunocompetent mice by orthotopic transplantation into the mammary gland or different routes of injection to induce organ-specific experimental metastasis, including intravenous, intracardiac, and caudal artery injection of tumor cells. Moreover, we describe protocols for sensitive detection and quantification of the metastatic burden.

Ornithine decarboxylase activity in prostate cancer.

Prostate cancer (PCa), the most common solid malignant neoplasm in men, is characterized using the Gleason score and diagnosed using prostate-specific antigen (PSA) biomarker. However, Gleason score and PSA-based diagnostics are not universal and have significant limitations. It is supposed that the ornithine decarboxylase activity (AODC) could be a suitable auxiliary biomarker for the PCa diagnosis or monitoring the therapeutic efficacy. AIM: To assess the relation between AODC in PCa tissues and the level of serum PSA with the Gleason score (GS) and the clinical stage. MATERIALS AND METHODS: 29 patients (48 to 79 years old) with prostate adenocarcinoma of different GS (6 to 10) and clinical stage (T1 to T4) were enrolled in the study. The AODC was analyzed in the PCa tissues by the modified spectrophotometric assay. RESULTS: The patients with PCa were distributed into two groups: with low AODC < 0.3 and high AODC > 0.45. In group with AODC < 0.3, the highest value of AODC was recorded in patients with the lowest GS (= 6), while in group with AODC > 0.45, the highest value of AODC was recorded in the patients with the highest GS (= 9-10). Furthermore, in group with AODC > 0.45, the highest value of AODC was registered in the patients with T1 or T4 stage. The highest levels of serum PSA were detected in T3-T4 cases and in cases with the highest GS. CONCLUSION: The patterns of AODC and serum PSA can be used as supplementary indices useful for monitoring PCa course.

Combined effect of chrysin and apigenin on inhibiting the development and progression of colorectal cancer by suppressing the activity of P38-MAPK/AKT pathway.

Either apigenin or chrysin alone has been found to exert anti-inflammatory and tumor suppressive effect. However, the combined effect of apigenin and chrysin on colorectal cancer (CRC) has not been fully clarified. We attempted to explore the effect of chrysin and apigenin on CRC and its related mechanism. SW480 and HCT-116 cells were treated with either apigenin or chrysin alone or two-drug combination at different doses of 5, 25, 50, 100 µM for optimal concentration determination. Then, we focused on the individual and combined effect of apigenin and chrysin on clonogenicity, apoptosis, metastasis-related behaviors of CRC cells by colony formation assay, cell scratch assay, flow cytometry, and transwell assay. The changes of the activation of P38-MAPK/AKT pathway were evaluated underlying apigenin and chrysin intervention, further after co-treated with P38-MAPK agonist anisomycin. Apigenin (25 µM) combined with chrysin (25 µM) were determined to be optimal. Treatment with the combination of apigenin (25 µM) and chrysin (25 µM) significantly reduced cell clone numbers, migration, and invasion ability, while increased the cell apoptosis in both CRC cell lines. The combined effect was higher than chrysin or apigenin alone. Meanwhile, p-P38 and p-AKT were significantly downregulated by chrysin and apigenin treatment. The tumor inhibitive effect of apigenin combined with chrysin was obviously reversed by adding P38 agonist, anisomycin. Apigenin (25 µM) combined with chrysin (25 µM) showed synergetic effect in inhibiting the growth and metastasis of CRC cells by suppressing the activity of P38-MAPK/AKT pathway.

mTOR Pathway Activation Assessed by Immunohistochemistry in Cervical Biopsies of HPV-associated Endocervical Adenocarcinomas (HPVA): Correlation With Silva Invasion Patterns.

The Silva pattern of invasion, recently introduced to stratify patients at risk for lymph node metastases in human papillomavirus-associated endocervical adenocarcinomas (HPVAs), can only be assessed in cone and loop electrosurgical excision procedure excisions with negative margins or in a hysterectomy specimen. Previous studies found associations between destructive stromal invasion patterns (Silva patterns B and C) and mutations in genes involved in the MEK/PI3K pathways that activate the mammalian target of rapamycin (mTOR) pathway. The primary aim of this study was to use cervical biopsies to determine whether markers of mTOR pathway activation associate with aggressive invasion patterns in matched excision specimens. The status of the markers in small biopsy specimens should allow us to predict the final and biologically relevant pattern of invasion in a resection specimen. Being able to predict the final pattern of invasion is important, since prediction as Silva A, for example, might encourage conservative clinical management. If the pattern in the resection specimen is B with lymphovascular invasion or C, further surgery can be performed 34 HPVA biopsies were evaluated for expression of pS6, pERK, and HIF1α. Immunohistochemical stains were scored semiquantitatively, ranging from 0 to 4+ with scores 2 to 4+ considered positive, and Silva pattern was determined in follow-up excisional specimens. Silva patterns recognized in excisional specimens were distributed as follows: pattern A (n=8), pattern B (n=4), and pattern C (n=22). Statistically significant associations were found comparing pS6 and pERK immunohistochemistry with Silva pattern (P=0.034 and 0.05, respectively). Of the 3 markers tested, pERK was the most powerful for distinguishing between pattern A and patterns B and C (P=0.026; odds ratio: 6.75, 95% confidence interval: 1.111-41.001). Although the negative predictive values were disappointing, the positive predictive values were encouraging: 90% for pERK, 88% for pS6 and 100% for HIF1α. mTOR pathway activation assessed by immunohistochemistry in cervical biopsies of HPVA correlate with Silva invasion patterns.

An initiative to assess the quality of Tanzanian cervical cancer specimens for HPV and telomerase detection.

The aim of our study was to assess the quality of Tanzanian cervical cancer specimens, evaluating telomerase alterations and human papilloma virus (HPV) infection in relation to histopathological characteristics since these biomarkers are not routinely analyzed. Thirty-two Tanzanian women with invasive cervical cancer were included in the study. Histopathological classification and all the analyses on tissue, including TERT immunohistochemistry, were performed at IRST IRCCS (Meldola, Italy). HPV typization was performed by pyrosequencing. FHACT™ was used to identify chromosomal aberrations. Nonparametric ranking statistics were used. The majority (75 %) of the cases analyzed were squamous carcinoma, while 12.5 % were adenocarcinoma. The presence of HPV infection was confirmed in 26/27 (96.3 %) cases. A high percentage of patients (88 %) were infected with HPV16 of whom 12 (44.4 %) with African type 1, and 4 (14.8 %) with African type 2. TERT expression evaluated in the entire case series showed a median H-score of 130 (range 3-270), with only one negative case. 88 % of the FISH-evaluable samples showed an amplification of the chromosomal region 3q26 (TERC) and/or 5p15, and 20q13, associated with a higher median expression of TERT (P = 0.0226). Despite pre-analytical problems in terms of sample fixation, we showed that the search for biomarkers such as HPV and telomerase is feasible in Tanzanian tissue. These markers could be important risk-stratification tools in this population.

P2Y2 receptor activation promotes esophageal cancer cells proliferation via ERK1/2 pathway.

Esophageal cancer is a prominent worldwide illness that is divided into two main subtypes: esophageal squamous cell carcinoma and esophageal adenocarcinoma. Mortality rates are alarming, and the understanding of the mechanisms involved in esophageal cancer development, becomes essential. Purinergic signaling is related to many diseases and among these various types of tumors. Here we studied the effects of the P2Y2 receptor activation in different types of esophageal cancer. Esophageal tissue samples of healthy controls were used for P2Y2R expression quantification. Two human esophageal cancer cell lines Kyse-450 (squamous cell carcinoma) and OE-33 (adenocarcinoma) were used to perform in vitro analysis of cell proliferation, migration, adhesion, and the signaling pathways involved in P2Y2R activation. Data showed that P2Y2R was expressed in biopsies of patients with ESCC and adenocarcinoma, as well as in the two human esophageal cancer cell lines studied. The RT-qPCR analysis demonstrated that OE-33 cells have higher P2RY2 expression than Kyse-450 squamous cell line. Results showed that P2Y2R activation, induced by ATP or UTP, promoted esophageal cancer cells proliferation and colony formation. P2Y2R blockage with the selective antagonist, AR-C 118925XX, led to decreased proliferation, colony formation and adhesion. Treatments with ATP or UTP activated ERK 1/2 pathway in ESCC and ECA cells. The P2Y2R antagonism did not alter the migration of esophageal cancer cells. Interestingly, the esophageal cancer cell lines presented a distinct profile of nucleotide hydrolysis activity. The modulation of P2Y2 receptors may be a promising target for esophageal cancer treatment.

Histone demethylase PHF8 drives neuroendocrine prostate cancer progression by epigenetically upregulating FOXA2.

Neuroendocrine prostate cancer (NEPC) is a more aggressive subtype of castration-resistant prostate cancer (CRPC). Although it is well established that PHF8 can enhance prostate cancer cell proliferation, whether PHF8 is involved in prostate cancer initiation and progression is relatively unclear. By comparing the transgenic adenocarcinoma of the mouse prostate (TRAMP) mice with or without Phf8 knockout, we systemically examined the role of PHF8 in prostate cancer development. We found that PHF8 plays a minimum role in initiation and progression of adenocarcinoma. However, PHF8 is essential for NEPC because not only is PHF8 highly expressed in NEPC but also animals without Phf8 failed to develop NEPC. Mechanistically, PHF8 transcriptionally upregulates FOXA2 by demethylating and removing the repressive histone markers on the promoter region of the FOXA2 gene, and the upregulated FOXA2 subsequently regulates the expression of genes involved in NEPC development. Since both PHF8 and FOXA2 are highly expressed in NEPC tissues from patients or patient-derived xenografts, the levels of PHF8 and FOXA2 can either individually or in combination serve as NEPC biomarkers and targeting either PHF8 or FOXA2 could be potential therapeutic strategies for NEPC treatment. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Secretory Phospholipase A2 IIa Mediates Expression of Growth Factor Receptors in Esophageal Adenocarcinoma.

BACKGROUND: Receptor tyrosine kinases of the epidermal growth factor receptor (EGFR) family such as human epidermal receptor-2 (HER2) are involved in the development and progression of esophageal adenocarcinoma (EAC). Prior studies have demonstrated that group IIa secretory phospholipase A2 (sPLA2 IIa) can function as a ligand for the EGFR family of receptors and lead to an increase in receptor signaling. AIMS: We hypothesized that sPLA2 IIa inhibition downregulates the expression of EGFR and HER-2 in EAC and through this mechanism decreases proliferation in EAC. METHODS: Normal human esophageal epithelium, Barrett's esophagus (BE), and EAC tissue samples were assayed for baseline expression of EGFR, HER-2, and sPLA2 IIa. sPLA2 IIa was attenuated via inhibitor or lentiviral knockdown in esophageal cell lines, and cells were assayed for EGFR and HER2 expression as well as proliferation. FLO1 EAC cells were injected into the flank of nude mice. After randomization, mice received daily group IIA sPLA2 inhibitor or a control solution, and tumor volume was measured with calipers. RESULTS: sPLA2 IIa, EGFR, and HER2 expression increased across the spectrum of normal esophageal epithelium to EAC. sPLA2 IIa inhibition and knockdown decreased the expression of HER-2 and EGFR and proliferation. Mice treated with sPLA2 IIa inhibitor had smaller tumors than controls. CONCLUSIONS: sPLA2 IIa inhibition decreases EGFR and HER2 expression and lowers proliferation of human EAC. The discovery of sPLA2 IIa inhibition's ability to attenuate growth factor receptor signaling underscores the exciting potential of sPLA2 IIa inhibitors as therapeutics in the treatment of EAC.