Abnormal expression of pRb, p16, and cyclin D1 in gastric adenocarcinoma and its lymph node metastases: relationship with pathological features and survival

Cyclin D1 expression, clinicopathological characteristics, and 2-year survival rate of gastric cancer in Cipto Mangunkusumo General Hospital

Background

Cyclin D1 is a protein that can increase the proliferation of cancer cells. Its expression has been found in various malignancies, including gastric cancer. Cyclin D1 examinations have not been routinely performed for gastric cancer cases in Indonesia. A recent study of cyclin D1 in gastric cancer was associated with lymph node involvement, metastasis, poor prognosis, and a lack of response to platinum chemotherapy.

Aim

This study aimed to determine the relationships among cyclin D1 expression, clinicopathological features, and 2-year survival rates in gastric cancer.

Materials and Methods

This retrospective cohort study used medical records and paraffin blocks of patients suffering from gastric cancer at Cipto Mangunkusumo General Hospital, Jakarta, between 2015 and 2020. Data analysis was performed using Statistical Package for the Social Sciences (SPSS) version 20. The data were collected from 39 subjects, most of whom experienced eating disorder (69.23%), weight loss (76.92%), melena (53.85%), and anemia (51.28%). Tumor location was mostly found in the cardia and corpus of the gaster.

Results

This study found that the proportion of overexpression of cyclin D1 was 30.77%. Cyclin D1 expression was greater in subjects with liver metastases (50% vs. 14.8%, P = 0.04). Cyclin D1 expression was not associated with tumor location, tumor, node, and metastasis (TNM) stage, or histopathological findings. Analysis of the 2-year survival rate did not find any differences between patients with cyclin D1 overexpression and those with cyclin D1 negative.

Conclusions

Cyclin D1 expression was associated with liver metastases in patients with gastric cancer.

Prognosis and survival study in patients with gastric adenocarcinoma and its relationship with pRb expression alteration: A retrospective IHC-based study

Background and Objective

Among cancers, gastric cancer has the fifth highest incidence worldwide and is the third most common mortality factor, which may have been due to inadequate knowledge of its molecular pathogenesis. The retinoblastoma gene (RB1), a tumor suppressor gene, may have a role in gastric cancer. This research aims to assess Rb expression as a prognostic marker to obtain more insight regarding gastric cancer.

Methods

This retrospective analytical study was done on 61 patients (45 males and 16 females) with gastric adenocarcinoma admitted from 2010 to 2012 in Shahid Sadoughi and Mortaz hospitals, Yazd, Iran. Demographic data, including age, gender, clinical signs and symptoms, and pathology reports, were retrieved from patients' hospital folders. Then, the altered Retinoblastoma gene expression was evaluated by immunohistochemistry studies. Acquired data were analyzed by SPSS software v.16. p < 0.05 was statistically considered meaningful.

Results

In this study, the ratio of men to women was higher (2.81:1), and the mean age of patients was 62.44 years. About 90.2% of patients died during the study. There was no meaningful relationship between the presence of pRb, the intensity of staining, the percentage of staining with patients' age, gender, tumor grading, and survival rate (p > 0.05). There was only a meaningful relationship between the grade of tumors and survival rate (p = 0.039).

Conclusion

Altered pRB expression is not common in gastric cancer and does not impact the survival and grading of tumors. Poorly differentiated tumors had an ominous outcome with the lowest survival time.

The Regulation of Cyclins and Cyclin-Dependent Kinases in the Development of Gastric Cancer

Gastric cancer predominantly occurs in adenocarcinoma form and is characterized by uncontrolled growth and metastases of gastric epithelial cells. The growth of gastric cells is regulated by the action of several major cell cycle regulators including Cyclins and Cyclin-dependent kinases (CDKs), which act sequentially to modulate the life cycle of a living cell. It has been reported that inadequate or over-activity of these molecules leads to disturbances in cell cycle dynamics, which consequently results in gastric cancer development. Manny studies have reported the key roles of Cyclins and CDKs in the development and progression of the disease in either in vitro cell culture studies or in vivo models. We aimed to compile the evidence of molecules acting as regulators of both Cyclins and CDKs, i.e., upstream regulators either activating or inhibiting Cyclins and CDKs. The review entails an introduction to gastric cancer, along with an overview of the involvement of cell cycle regulation and focused on the regulation of various Cyclins and CDKs in gastric cancer. It can act as an extensive resource for developing new hypotheses for future studies.

Mantle Cell Lymphoma Presenting as Acute Abdominal Syndrome: A Rare Case Report and Literature Review

BACKGROUND

Acute abdominal syndrome can be caused by several possible reasons. The most common causes are perforation of a gastroduodenal ulcer, peritonitis, intestinal obstructions, and perforation of an appendix or fallopian tube. Fever and pain can be caused by an appendicitis or sigmoiditis. Appendiceal lymphoma is a rare disease that is usually found incidentally during appendectomy. Most of the cases are non-Hodgkin's lymphomas. Mantle cell lymphoma is an aggressive B-cell non-Hodgkin's lymphoma with a poorer prognosis than other B-cell lymphomas; thus, a definitive diagnosis is essential.

CASE SUMMARY

A 60-year-old man presented with right lower quadrant pain. He denied any nausea, vomiting or anorexia and was afebrile. The physical examination revealed right lower quadrant abdomen tenderness. The computed tomography scan revealed periappendiceal fatty stranding with a swollen appendix, approximately 2 cm in diameter and prominent paraaortic, portacaval and mesenteric lymph nodes. A diagnosis of acute appendicitis was made, and laparoscopic appendectomy was performed immediately. The subsequent pathological examination revealed severe congestion with lymphoid hyperplasia. The immunohistochemistry stains revealed positive staining for cluster of differentiation (CD) CD20, B-cell lymphoma-2 (Bcl-2), cyclin D1, SRY-box transcription factor-11 (SOX-11), immunoglobulin D (IgD) and immunoglobulin M (IgM) but negative staining for CD3, CD5, CD10 and CD23. 18F-FDG positron emission tomography showed peripheral lymph node involvement, while the bone marrow biopsy showed negative findings. Therefore, a diagnosis of mantle cell lymphoma, Ann Arbor stage IVA, was made. The patient received postoperative combination chemotherapy and remained in a stable condition over a 1-year follow-up period.

CONCLUSION

We report an uncommon case that initially presented as acute appendicitis, for which a final diagnosis of mantle cell lymphoma was made. In comparison with other B-cell lymphomas, mantle cell lymphoma has a poorer prognosis, and positive immunochemical staining of cyclin D1 and SOX-11 is useful for differentiating mantle cell lymphoma from other appendiceal lymphomas and treating patients appropriately. Physicians and nursing staff should be also aware of the associated complications and management in these patients.

The Role and Clinical Implications of the Retinoblastoma (RB)-E2F Pathway in Gastric Cancer

Gastric cancer is the most common malignant tumor in the digestive tract, with very high morbidity and mortality in developing countries. The pathogenesis of gastric cancer is a complex biological process mediated by abnormal regulation of proto-oncogenes and tumor suppressor genes. Although there have been some in-depth studies on gastric cancer at the molecular level, the specific mechanism has not been fully elucidated. RB family proteins (including RB, p130, and p107) are involved in cell cycle regulation, a process that largely depends on members of the E2F gene family that encode transcriptional activators and repressors. In gastric cancer, inactivation of the RB-E2F pathway serves as a core transcriptional mechanism that drives cell cycle progression, and is regulated by cyclins, cyclin-dependent kinases, cyclin-dependent kinase inhibitors, p53, Helicobacter pylori and some other upstream molecules. The E2F proteins are encoded by eight genes (i.e. E2F1 to E2F8), each of which may play a specific role in gastric cancer. Interestingly, a single E2F such as E2F1 can activate or repress transcription, and enhance or inhibit cell proliferation, depending on the cell environment. Thus, the function of the E2F transcription factor family is very complex and needs further exploration. Importantly, the presence of H. pylori in stomach mucosa may affect the RB and p53 tumor suppressor systems, thereby promoting the occurrence of gastric cancer. This review aims to summarize recent research progress on important roles of the complex RB-E2F signaling network in the development and effective treatment of gastric cancer.

Prognostic Value of Cyclin D1 and CD44 Expression in Gastric Adenocarcinoma

BACKGROUND

Worldwide, gastric carcinoma (GC) is the 5th most common malignancies in both sexes representing 6.8% of the total fatalities and is the 3rd leading cause of cancer death representing 8.8% of total fatalities. In Egypt, GC considers the 12th leading cause of cancer death representing 2.2% of the total cancer mortality. A growing body of evidence supports that cancer stem cells (CSCs) are resistant to chemotherapy or radiation, and the cell adhesion molecule CD44 has been identified as a cell surface marker associated with cancer stem cell in several types of tumors including gastric cancer. CD44 regulates gastric stem cell proliferation by increasing cyclin D1 expression which represents an important regulatory protein in the cell cycle transition from G1 phase to S phase. This study aimed to investigate whether cyclin D1 and CD44 can be used as prognostic indicators in gastric cancer.

MATERIAL AND METHODS

Forty formalin-fixed and paraffin-embedded gastric tissues, obtained from patients who underwent endoscopic resection or surgical resection, constituted the group of our study. The immunohistochemical expression of cyclin D1 and CD44 was examined and correlated with clinical-pathological parameters and outcome of the patients.

RESULTS

Overexpression of CD44 and cyclin D1 was noted (in of 55 and 50% respectively). Cyclin D1 and CD44 positive expressions in GC were positively correlated with tumor differentiation (p = 0.020, p = 0.004 respectively), TNM stage (p < 0.001 for both), poor survival (p < 0.001 for both), and with increased rate of recurrence (p = 0.020, p = 0.005 respectively).

CONCLUSION

CD44 and cyclin D1 were associated with poor prognosis in gastric cancer, and so, they comprise an attractive target for anticancer drug development.

Identifying Mutually Exclusive Gene Sets with Prognostic Value and Novel Potential Driver Genes in Patients with Glioblastoma

The pathogenesis and prognosis of glioblastoma (GBM) remain poorly understood. Mutual exclusivity analysis can distinguish driver genes and pathways from passenger ones. The purpose of this study was to identify mutually exclusive gene sets (MEGSs) that have prognostic value and to detect novel driver genes in GBM. The genomic alteration profile and clinical information were derived from The Cancer Genome Atlas, and the MEGSA method was used to identify the MEGS. Next, we performed survival analysis and constructed a risk prediction model for prognostic stratification. Leave-one-out cross-validation and permutation test were used to evaluate its performance. Finally, we identified 21 statistically significant MEGSs. We found that the MEGS in the RB pathway was significantly associated with poor prognosis, after adjusting for age and gender (HR = 1.837, 95% CI: 1.192-2.831). Based on the risk prediction model, 208 (80.9%) and 49 (19.1%) patients were assigned to high- and low-risk groups, respectively (log-rank: p < 0.001, adjusted p=0.001). Additionally, we found that SPTA1, a novel gene involved in the MEGS, was mutually exclusive with members of cell cycle, P53, and RB pathways. In conclusion, the MEGS in the RB pathway had considerable clinical value for GBM prognostic stratification. Mutated SPTA1 may be involved in GBM development.

Protein expression profiles and clinicopathologic characteristics associate with gastric cancer survival

BACKGROUND

Prognosis remains one of most crucial determinants of gastric cancer (GC) treatment, but current methods do not predict prognosis accurately. Identification of additional biomarkers is urgently required to identify patients at risk of poor prognoses.

METHODS

Tissue microarrays were used to measure expression of nine GC-associated proteins in GC tissue and normal gastric tissue samples. Hierarchical cluster analysis of microarray data and feature selection for factors associated with survival were performed. Based on these data, prognostic scoring models were established to predict clinical outcomes. Finally, ingenuity pathway analysis (IPA) was used to identify a biological GC network.

RESULTS

Eight proteins were upregulated in GC tissues versus normal gastric tissues. Hierarchical cluster analysis and feature selection showed that overall survival was worse in cyclin dependent kinase (CDK)2, Akt1, X-linked inhibitor of apoptosis protein (XIAP), Notch4, and phosphorylated (p)-protein kinase C (PKC) α/β2 immunopositive patients than in patients that were immunonegative for these proteins. Risk score models based on these five proteins and clinicopathological characteristics were established to determine prognoses of GC patients. These proteins were found to be involved in cancer related-signaling pathways and upstream regulators were identified.

CONCLUSION

This study identified proteins that can be used as clinical biomarkers and established a risk score model based on these proteins and clinicopathological characteristics to assess GC prognosis.

Gastric hepatoid adenocarcinomas are a genetically heterogenous group; most tumors show chromosomal instability, but MSI tumors do exist

The Cancer Genome Atlas Research Network classified gastric adenocarcinoma into four molecular subtypes: (1) Epstein-Barr virus-positive (EBV), (2) microsatellite-instable (MSI), (3) chromosomal instable (CIN), and (4) genomically stable (GS). The molecular subtypes of gastric hepatoid adenocarcinomas are still largely unknown. We analyzed 52 hepatoid adenocarcinomas for the expression of surrogate markers of molecular subtypes (MLH1, p53, and EBER in situ hybridization) and some biomarkers (p21, p16, Rb, cyclin D1, cyclin E, β-catenin, Bcl-2, IMP3, ARID1A and HER2), and mutations of TP53, CTNNB1, KRAS, and BRAF. We analyzed 36 solid-type poorly differentiated adenocarcinomas as a control group. Hepatoid adenocarcinomas were categorized as follows: EBV group (EBER-positive), no cases (0%); MSI group (MLH1 loss), three cases (6%); "CIN or GS" (CIN/GS) group (EBER-negative, MLH1 retained), 49 cases (94%). In the CIN/GS group, most of the tumors (59%) had either p53 overexpression or TP53 mutation and a coexisting tubular intestinal-type adenocarcinoma component (90%), suggesting that most hepatoid adenocarcinomas should be categorized as a true CIN group. Hepatoid adenocarcinomas showed relatively frequent expressions of HER2 (score 3+/2+: 21%/19%). Hepatoid adenocarcinomas showed shorter survival, more frequent overexpressions of p16 (67%) and IMP3 (98%) than the control group. None of hepatoid adenocarcinomas had KRAS or CTNNB1 mutations except for one case each, and no hepatoid adenocarcinomas had BRAF mutation. In conclusion, gastric hepatoid adenocarcinomas are a genetically heterogenous group. Most hepatoid adenocarcinomas are "CIN," but a small number of hepatoid adenocarcinomas with MSI do exist. Hepatoid adenocarcinomas are characterized by overexpressions of p16 and IMP3.

MicroRNA-378 enhances migration and invasion in cervical cancer by directly targeting autophagy-related protein 12

Cervical cancer is the second most common type of cancer among women worldwide and a leading cause of mortality in women. Metastases reduce the overall survival rate in patients with cervical cancer. Thus, it is clinically urgent to investigate the molecular mechanism of cervical cancer metastasis. The aim of the present study was to investigate the mechanism of microRNA (miR)‑378 in the metastasis of cervical cancer. In the present study, miR‑378 expression levels were significantly upregulated in cervical cancer tissues and cervical intraepithelial neoplasia III tissues when compared with normal cervix tissues. Re‑expression of miR‑378 significantly promoted tumor migration and invasion in vitro, and metastasis in vivo, while downregulation of miR‑378 suppressed the effect in vitro. Luciferase reporter assay revealed that autophagy‑related protein 12 (ATG12) was a direct target of miR‑378 and its expression was downregulated by miR‑378. In cervical cancer tissues with lymph node metastasis, miR‑378 was upregulated while ATG12 was downregulated when compared with lymph node negative cases. To the best of our knowledge, the present study is the first to provide evidence that miR‑378 may be associated with ATG12. Collectively, the data of the present study suggested that miR‑378 may function as an oncogene by promoting metastasis in cervical cancer. The finding that miR‑378 targets ATG12 indicated that miR‑378 may have a potential role in autophagy. These findings may provide novel insights into the mechanism of metastasis in cervical cancer and a novel therapeutic target for the treatment of cervical cancer.

Identification of differentially expressed genes and biological pathways in bladder cancer

The purpose of the present study was to identify key genes and investigate the related molecular mechanisms of bladder cancer (BC) progression. From the Gene Expression Omnibus database, the gene expression dataset GSE7476 was downloaded, which contained 43 BC samples and 12 normal bladder tissues. GSE7476 was analyzed to screen the differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed for the DEGs using the DAVID database, and a protein-protein interaction (PPI) network was then constructed using Cytoscape software. The results of the GO analysis showed that the upregulated DEGs were significantly enriched in cell division, nucleoplasm and protein binding, while the downregulated DEGs were significantly enriched in ‘extracellular matrix organization’, ‘proteinaceous extracellular matrix’ and ‘heparin binding’. The results of the KEGG pathway analysis showed that the upregulated DEGs were significantly enriched in the ‘cell cycle’, whereas the downregulated DEGs were significantly enriched in ‘complement and coagulation cascades’. JUN, cyclin-dependent kinase 1, FOS, PCNA, TOP2A, CCND1 and CDH1 were found to be hub genes in the PPI network. Sub-networks revealed that these gene were enriched in significant pathways, including the ‘cell cycle’ signaling pathway and ‘PI3K-Akt signaling pathway’. In summary, the present study identified DEGs and key target genes in the progression of BC, providing potential molecular targets and diagnostic biomarkers for the treatment of BC.

P16 promotes the growth and mobility potential of breast cancer both in vitro and in vivo: the key role of the activation of IL-6/JAK2/STAT3 signaling

P16 is the product of cyclin-dependent kinase 2 (CDKN2A) gene and plays multi-pronged roles in the cancer progression. Breast cancer (BC) is the most commonly diagnosed cancer type among females. In the current study, the potential function of P16 in the growth and metastasis of BC was investigated. Firstly, the expression statuses of P16 in different cancer types were investigated using Oncomine database and validated with corresponding cancer cell lines. Afterwards, the expression of P16 was knocked down in BC cell line BT-549 and the effect on the cell proliferation, sensitivity to paclitaxel (TAX), apoptosis, migration, and invasion abilities was assessed using CCK-8, Edu, flow cytometry, scratch, and transwell assays, respectively. The influence of P16 inhibition and P16 overexpression on the activity of IL-6/JAK/STAT3 signaling was explored. Additionally, the effect of P16 inhibition on the tumor growth was verified with a BC xenograft mice model. The abnormal expression of P16 was detected in BC cell line BT-549 as well as colorectal cancer and osteosarcoma cell lines. The inhibition of P16 suppressed the cell proliferation, invasion, and migration abilities while induced the apoptosis and sensitivity to TAX in BT-549 cells. At molecular level, P16 knockdown inhibited the expression of IL6ST and Survivin, and the phosphorylation of JAK2 and STAT3. However, the induced expression of P16 in P16-knockdown BT-549 cells restored the activity of IL-6/JAK2/STAT3 pathway. The results of in vitro assays were confirmed with BC xenograft models: the inhibition of P16 decreased the tumor growth rate. Findings outlined in the current study demonstrated that the inhibition of P16 decreased the growth and metastasis potential of BC cells by inhibiting IL-6/JAK2/STAT3 signaling.

Histologic and immunohistochemical differences between hereditary and sporadic diffuse gastric carcinoma

We aimed to identify histopathologic features unique in hereditary diffuse gastric cancer (HDGC) by comparing with its sporadic counterpart (SDGC). 11 patients with confirmed CDH1 mutation who were found to have HDGC in a prophylactic total gastrectomy were collected. Median age of HDGC patients was 39 years (range 24-57). All HDGC cases had intramucosal signet ring cell carcinoma. Twenty-three invasive tumor foci from 7 patients with HDGC were available for ancillary studies, and we evaluated each focus separately. Almost all foci (20/23) showed two distinct tumor cell populations, namely, large signet ring cells and small signet ring cells. The large cells were located just beneath the surface epithelium and were positive for mucicarmine and pCEA, while the small cells were found in the deeper lamina propria and were mostly negative for mucicarmine and pCEA. A subset of small cells (6 foci from two resected stomachs) showed poorly differentiated morphology with p16 positivity. All other tumor cells with well-differentiated signet ring cell morphology were negative for p16. In contrast, 18 of 20 SDGCs were positive for p16. In addition, all HDGCs were negative for CDX2, while 19 of 20 SDGCs were positive. We propose that there are three distinct tumor cell populations in HDGC: well-differentiated large cells, well-differentiated small cells, and poorly differentiated small cells, and that the latter group with aberrant p16 expression may represents a more aggressive phenotype. The absence of CDX2 in HDGC suggests that it may develop along a carcinogenetic pathway different from that of SDGC.

Palbociclib-induced autophagy and senescence in gastric cancer cells

Targeting cyclin D-CDK4/6 kinase complexes has recently been shown to increase the survival of breast cancer patients with estrogen receptor positive breast tumors. Based on these outcomes, CDK4/6 inhibitors are currently being tested, alone o in combination with other drugs, in the treatment of other malignancies characterized by hyper-activation of cyclin D-CDK4/6 complexes. Nonetheless, a better understanding of the cellular processes that are implemented in response to CDK4/6 inhibition is necessary to expand the therapeutic window and confront the development of drug resistance. Herein, we show that, similar to mammary cells, gastric cancer cells are sensitive to the CDK4/6 inhibitor Palbociclib. Inhibition of CDK4/6 in gastric cancer cells leads to the implementation of cellular senescence. However, whether or not this response is accompanied by induction of autophagy seems to depend on both the pRB and p53 status. In cells retaining expression of both tumor suppressive proteins (AGS gastric cancer cells), exposure to Palbociclib induces senescence and autophagy. However, the simultaneous blockade of CDK4/6 and autophagy in these cells exacerbates the senescence phenotype, an indication that autophagy in these experimental settings represents an adaptive mechanism that promotes cell survival rather than being an effector mechanism of senescence. Interestingly, knocking down p53 resulted in senescence reduction and autophagy blockade, the latter apparently involving a disruption of the degradation of autophagosome cargo.

Prognostic values of four Notch receptor mRNA expression in gastric cancer

Notch ligands and receptors are frequently deregulated in several human malignancies including gastric cancer. The activation of Notch signaling has been reported to contribute to gastric carcinogenesis and progression. However, the prognostic roles of individual Notch receptors in gastric cancer patients remain elusive. In the current study, we accessed the prognostic roles of four Notch receptors, Notch 1-4, in gastric cancer patients through "The Kaplan-Meier plotter" (KM plotter) database, in which updated gene expression data and survival information include a total of 876 gastric cancer patients. All four Notch receptors' high mRNA expression was found to be correlated to worsen overall survival (OS) for all gastric cancer patients followed for 20 years. We further accessed the prognostic roles of individual Notch receptors in different clinicopathological features using Lauren classification, pathological grades, clinical grades, HER2 status and different choices of treatments of gastric cancer patients. These results indicate that there are critical prognostic values of the four Notch receptors in gastric cancer. This information will be useful for better understanding of the heterogeneity and complexity in the molecular biology of gastric cancer and to develop tools to more accurately predict their prognosis.

Selective CDK7 inhibition with BS-181 suppresses cell proliferation and induces cell cycle arrest and apoptosis in gastric cancer

Cyclin-dependent kinase (CDK) family members have been considered as attractive therapeutic targets for cancer. In this study, we aim to investigate the anticancer effects of a selective CDK7 inhibitor, BS-181, in gastric cancer (GC) cell line. Human GC cells (BGC823) were cultured with or without BS-181 at different concentrations for 24-72 hours. BS-181 significantly reduced the activity of CDK7 with downregulation of cyclin D1 and XIAP in GC cells. Treatment with BS-181 induced cell cycle arrest and apoptosis. The expression of Bax and caspase-3 was significantly increased, while Bcl-2 expression was decreased in cells treated with BS-181. In addition, the inhibition of CDK7 with BS-181 resulted in reduced rates of proliferation, migration, and invasion of gastric cells. Those results demonstrated the anticancer activities of selective CDK7 inhibitor BS-181 in BGC823 cells, suggesting that CDK7 may serve as a novel therapeutic target or the treatment of GC.

Dysregulation of the Rb pathway in recurrent pleomorphic adenoma of the salivary glands

Pleomorphic adenoma (PA) is the most common salivary gland neoplasm, and while mostly benign, recurrences (RPA) and malignant transformation to carcinoma ex-PA (CXPA) do occur. Cell cycle proteins important in its tumorigenesis have been studied as markers for PA with a high risk of RPA or CXPA. The aim of the present study was to investigate cell cycle markers p-16, cyclin D1, CDK4, E2F, and retinoblastoma (Rb) in this context. Expression of p16, cyclin D1, E2F, CDK4, and Rb was studied by immunohistochemistry in 24 cases of PA, 21 of RPA, and 2 of CXPA. The presence of HPV was assessed by in situ hybridization. Immunostaining for p16 and cyclin D1 was negative or weakly positive in most cases of PA while strongly positive in the majority of RPA and both CXPA cases. Staining for Rb and CDK4 was either negative or weakly positive in PA, RPA, and CXPA. Expression of E2F was stronger in RPA and CXPA than in PA. Nuclear reactivity for HPV was not observed in any case. In conclusion, the strong staining for p16, cyclinD1, and E2F in RPA and CXPA, while weak or negative in PA, suggests that these proteins might be involved in recurrence and malignant transformation of PA.

Biomarkers for gastric cancer: Progression in early diagnosis and prognosis (Review)

Gastric cancer is one of leading causes of cancer-related mortality worldwide and is a notable disease due to its heterogeneity. Recently, numerous studies have investigated the molecular basis of gastric cancer, involving the alteration of pathogenesis, and invasion and metastasis. With the development of modern technologies, various novel biomarkers had been identified that appear to possess diagnostic and prognostic value; therefore, the present review describes our current knowledge of biomarkers for the early diagnosis and prognosis of gastric cancer. Classic biomarkers for gastric cancer diagnosis include carcinoembryonic antigen and cancer antigen 19-9, while microRNA and DNA hypomethylation are proposed as novel biomarkers. Excluding classical biomarkers, biomarkers for determining the progression and prognosis of gastric cancer focus on targeting microRNAs, epigenetic alterations and genetic polymorphisms.

Molecular genetics of gastric adenocarcinoma in clinical practice

The molecular genetics of gastric carcinoma (GC) dictates their biology and clinical behavior. The two morphologically distinct types of gastric carcinoma by Lauren classification, i.e., intestinal and diffuse cell types, have a significant difference in clinical outcome. These two types of GC have different molecular pathogenetic pathways with unique genetic alterations. In addition to environmental and other etiologies, intestinal type GC is associated with Helicobacter pylori (H. pylori) infection and involves a multistep molecular pathway driving the normal epithelium to intestinal metaplasia, dysplasia, and malignant transformation by chromosomal and/or microsatellite instability (MSI), mutation of tumor suppressor genes, and loss of heterozygosity among others. Diffuse type shows no clear causal relationship with H. pylori infection, but is commonly associated with deficiency of cell-cell adhesion due to mutation of the E-cadherin gene (CDH1), and a manifestation of the hereditary gastric cancer syndrome. Thus, detection of CDH1 mutation or loss of expression of E-cadherin may aid in early diagnosis or screening of diffuse type GC. Detection of certain genetic markers, for example, MSI and matrix metalloproteinases, may provide prognostic information, particularly for intestinal type. The common genetic alterations may offer therapeutic targets for treatment of GC. Polymorphisms in Thymidylate synthase to metabolize 5-fluorouracil, glutathione S-transferase for degradation of Cisplatin, and amplification/overexpression of human epidermal growth factor receptor 2 targeted by monoclonal antibody Trastuzumab, are a few examples. P13K/Akt/mTOR pathway, c-Met pathways, epidermal growth factor receptor, insulin-like growth factor receptor, vascular endothelial growth factor receptor fibroblast growth factor receptor, and micro RNAs are several potential therapeutic biomarkers for GC under investigation.

Molecular markers of mucosa harboring gastric adenomas

CONTEXT

Gastric adenoma is a precursor lesion of the adenocarcinoma.

OBJECTIVE

To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma.

METHODS

Forty gastric specimens from 20 patients were classified as intestinal (MUC2-goblet cell mucin) or foveolar (MUC5AC-gastric-foveolar mucin) adenomas. Immunohistochemistry was performed using streptavidin-biotin-complex method.

RESULTS

Twelve (60%) patients were men. The mean age was 67.9±12.9 years-old. Intestinal adenomas were detected in 13 (65%) patients and gastric type in 7 (35%). Low-grade dysplasia was present in 13 (65%) of the adenomas, high-grade in 3 (15%), and adenocarcinoma within the polyp in 4 (20%). Six (30%) patients had synchronous adenocarcinoma. p53 immunoexpression was observed in 6/20 (30%) of adenomas, and in 2/6 (33.3%) of synchronous tumors. There was an association between p53 immunoexpression and intestinal type of adenoma/tumor, P=0.04. There was no association between p16ink4a, Bcl-2, cyclin D and Ki-67 and adenoma clinicopathological characteristics.

CONCLUSION

Immunohistochemistry may be useful to classify the adenomas subtypes and may define the pathway of adenoma to carcinoma sequence.

Molecular biomarkers in esophageal, gastric, and colorectal adenocarcinoma

Cancers of the esophagus, stomach and colon contribute to a major health burden worldwide and over 20% of all cancer deaths. Biomarkers that should indicate pathogenic process and are measureable in an objective manner for these tumors are rare and not established in the clinical setting. In general biomarkers can be very useful for cancer management as they can improve clinical decision-making regarding diagnosis, surveillance, and therapy. Biomarkers can be different types of molecular entities (such as DNA, RNA or proteins), which can be detected, in different tissues or body fluids. However, more important is the type of biomarker itself, which allows diagnostic, prognostic or predictive analyses for different clinical problems. This review aims to systematically summarize the recent findings of genetic and epigenetic markers for gastrointestinal tumors within the last decade. While many biomarkers seem to be very promising, especially if used as panels, further development is urgently needed to address practical considerations of biomarkers in cancer treatment.

β-Ionone arrests cell cycle of gastric carcinoma cancer cells by a MAPK pathway

β-Ionone is an end ring analog of β-carotenoid which has been shown to possess potent anti-proliferative activity both in vitro and in vivo. To investigate the possible inhibitory effects of β-ionone, we studied cell growth characteristics, DNA synthesis, cell cycle progression, as well as mitogen-activated protein kinases (MAPKs) pathways in the human gastric adenocarcinoma cancer cell line (SGC-7901). Our results show that cell growth and DNA synthesis were inhibited, and the cell cycle was arrested at the G0/G1 phase in a dose-dependent manner in cells treated with β-ionone (25, 50, 100 and 200 μmol/L) for 24 h. We found that the β-ionone significantly decreased the extracellular signal-regulated kinase protein expression and significantly increased the levels of p38 and Jun-amino-terminal kinase protein expression (P < 0.01). β-Ionone also inhibited cell cycle-related proteins of Cdk4, Cyclin B1, D1 and increased p27 protein expression in SGC-7901 cells. These results suggested that the cell cycle arrest observed may be regulated through a MAPK pathway by transcriptional down-regulation of cell cycle proteins. These results demonstrate potent ability of β-ionone to arrest cell cycle of SGC-7901 cells and decrease proliferation.

The incidence and prognostic value of HER2 overexpression and cyclin D1 expression in patients with gastric or gastroesophageal junction adenocarcinoma in Israel

Human epidermal growth factor 2 (HER2) positivity rates for gastric or gastroesophageal junction (GEJ) adenocarcinoma have been reported at 15-25%. Cyclin D1 (BCL1) is a non-specific proliferative marker. The prognostic significance of HER2 and cyclin D1 is inconclusive, with contradictory data. The aim of this study was to evaluate the incidence of HER2 overexpression in gastric or GEJ patients. The presence of a possible correlation between HER2 status and cyclin D1 staining was assessed; both were evaluated as prognostic markers for survival. The clinical data and histological specimens of 150 consecutive patients diagnosed with gastric or GEJ adenocarcinoma, and treated at our hospital from June 2005 to March 2009, were analyzed. Pathological specimens were immunohistochemically stained for HER2. Immunoreactivity was determined according to the scoring system for gastric carcinoma. Cyclin D1 immunoreactivity was also tested. The results demonstrated that HER2 was positive in 14/150 (9.3%) patients. HER2-positive (HER2(+)) and HER2-negative (HER2(-)) patients did not differ significantly with regard to other clinicopathological parameters. In a multivariate analysis, HER2 positivity was revealed to be a poor prognosis variable (P=0.046; 95% CI, 1.03-3.58). In patients with non-metastatic disease, median survival was 59 months for HER2(-) and 42 months for HER2+ patients, but this difference was not significant. In patients with metastatic disease, median survival was 9.5 months and 2.5 months for HER2(-) and HER2+ patients, respectively (P=0.041). Cyclin D1 was not idemonstrated to be a prognostic factor and was not associated with HER2 overexpression. The rate of positive HER2 status in the current group of unselected patients with gastric and GEJ adenocarcinoma was relatively low compared with that observed in the literature. Nevertheless, HER2 positivity was associated with a poor prognosis.

Methylation and Expression of Retinoblastoma and Transforming Growth Factor-β1 Genes in Epstein-Barr Virus-Associated and -Negative Gastric Carcinomas

Background. Retinoblastoma (RB) and transforming growth factor-β1 (TGF-β1) are important tumor-related factors. Methods. A series of 30 EBV-associated gastric carcinoma (EBVaGC) and 38 matched EBV-negative gastric carcinoma (EBVnGC) tissues were examined for the promoter methylation of RB by methylation-specific PCR (MSP) method. The expression of RB and TGF-β1 in gastric carcinoma tissues was detected by immunohistochemistry. Results. The methylation rate of RB gene in EBVaGC and EBVnGC was 80.0% (24/30) and 50.0% (19/38), respectively. The difference of RB methylation rate between EBVaGC and EBVnGC was significant (χ² = 6.490, P = 0.011). There was no significant difference for RB expression between EBVaGC (43.3%, 13/30) and EBVnGC (63.2%, 24/38), and also for TGF-β1 between EBVaGC (56.7%, 17/30) and EBVnGC (63.2%, 24/38). RB methylation was not reversely correlated with RB expression in gastric carcinoma tissues (χ² = 2.943, P = 0.086, r = 0.208). RB methylation, loss expression of RB, and TGF-β1 expression were significantly associated with tumor invasion and lymph node metastasis (P < 0.05), but was not associated with sex, age, histological subtype (differentiation status) and tumor location. Conclusions. Methylation of RB is a common event in gastric carcinomas and EBV induces methylation of RB in EBVaGC, which may contribute to the development of gastric carcinomas. EBV has no significant effect on induction of TGF-β1 expression. Detection of RB methylation, RB expression, and TGF-β1 expression may be helpful to judge the status of tumor invasion and lymph node metastasis in gastric carcinomas.

Runx3 suppresses gastric cancer metastasis through inactivation of MMP9 by upregulation of TIMP-1

Recent studies have suggested that loss of RUNX3 expression is involved with gastric tumor metastasis. However, the precise mechanism of RUNX3-mediated suppression of tumor metastasis remains elusive. We aimed to clarify the effect of RUNX3 on tumor metastasis in gastric cancer cell lines and tumors. Immunohistochemistry revealed that RUNX3 was significantly decreased in metastatic gastric cancer. Gelatin zymography and Western blot showed that instead of regulating matrix metalloproteinase 9 (MMP9) expression, RUNX3 expression inhibited MMP9 enzyme activity, and this was consistent with the upregulation of tissue inhibitor of metalloproteinases 1 (TIMP1) by RUNX3. TIMP1 siRNA treatment impaired RUNX3-mediated suppression of gastric cancer cell invasion. Reporter assays demonstrated regulation of TIMP-1 by RUNX3. Two RUNX3 binding sites were identified in the TIMP-1 promoter and direct interaction of RUNX3 with the TIMP-1 promoter was confirmed in vitro and in vivo. These findings provide evidence for RUNX3-mediated suppression of gastric cancer invasion and metastasis and define a novel molecular mechanism that for the metastasis-inhibiting activity of RUNX3. These data may be applied in the development of RUNX3 for gastric cancer metastasis diagnostics and therapeutics.

Overexpressions of Cyclin B1, cdc2, p16 and p53 in human breast cancer: the clinicopathologic correlations and prognostic implications

PURPOSE

The molecular mechanisms that are responsible for the initiation and progression of breast cancers are largely unknown. This study was to analyze the cyclin B1, cdc2, p53 and p16 tumor suppressor genes in human breast cancer.

MATERIALS AND METHODS

To investigate the role of cyclin B1, cdc2, p53 and p16 in the pathogenesis and progression of breast carcinomas, 98 cases of breast cancers were examined by immunohistochemical method. The correlations of cyclin B1, cdc2, p53 and p16 expression with various clinico-pathologic findings were analysed.

RESULTS

In the normal breast tissues, cyclin B1, cdc2 and p16 were weakly expressed, while p53 was not expressed. On the other hand, cyclin B1, cdc2, p53 and p16 were overexpressed in breast cancer, showing correlation between the expression of cyclin B1 and cdc2 and breast cancers (p=0.00). The overexpressions of cdc2 and p16 were correlated with an infiltrative tumor border pattern and this was statistically significant (p<0.05). In addition, the overexpression of cdc2 was correlated with histologic high grade carcinomas (p=0.00).

CONCLUSION

Cyclin B1 and cdc2 appeared to be involved in the genesis or progression of breast cancers. In addition, the overexpressions of p16 and p53 may play important roles in more aggressive tumor and the overexpression of cdc2 is associated with progression of tumor to a higher grade of breast carcinomas. The deranged overexpressions of cyclin B1, cdc2, p16 and p53 may play an important role in human breast carcinogenesis.

Expression ratio of CCND1 to CDKN2A mRNA predicts RB1 status of cultured cancer cell lines and clinical tumor samples

Background

The retinoblastoma product (RB1) is frequently deregulated in various types of tumors by mutation, deletion, or inactivation through association with viral oncoproteins. The functional loss of RB1 is recognized to be one of the hallmarks that differentiate cancer cells from normal cells. Many researchers are attempting to develop anti-tumor agents that are preferentially effective against RB1-negative tumors. However, to identify patients with RB1-negative cancers, it is imperative to develop predictive biomarkers to classify RB1-positive and -negative tumors.

Results

Expression profiling of 30 cancer cell lines composed of 16 RB1-positive and 14 RB1-negative cancers was performed to find genes that are differentially expressed between the two groups, resulting in the identification of an RB1 signature with 194 genes. Among them, critical RB1 pathway components CDKN2A and CCND1 were included. We found that microarray data of the expression ratio of CCND1 and CDKN2A clearly distinguished the RB1 status of 30 cells lines. Measurement of the CCND1/CDKN2A mRNA expression ratio in additional cell lines by RT-PCR accurately predicted RB1 status (12/12 cells lines). The expression of CCND1/CDKN2A also correlated with RB1 status in xenograft tumors in vivo. Lastly, a CCND1/CDKN2A assay with clinical samples showed that uterine cervical and small cell lung cancers known to have a high prevalence of RB1-decifiency were predicted to be 100% RB1-negative, while uterine endometrial or gastric cancers were predicted to be 5-22% negative. All clinically normal tissues were 100% RB1-positive.

Conclusions

We report here that the CCND1/CDKN2A mRNA expression ratio predicts the RB1 status of cell lines in vitro and xenograft tumors and clinical tumor samples in vivo. Given the high predictive accuracy and quantitative nature of the CCND1/CDKN2A expression assay, the assay could be utilized to stratify patients for anti-tumor agents with preferential effects on either RB1-positive or -negative tumors.

Genomic and genetic alterations influence the progression of gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide, although the incidence has gradually decreased in many Western countries. Two main gastric cancer histotypes, intestinal and diffuse, are recognised. Although most of the described genetic alterations have been observed in both types, different genetic pathways have been hypothesized. Genetic and epigenetic events, including 1q loss of heterozygosity (LOH), microsatellite instability and hypermethylation, have mostly been reported in intestinal-type gastric carcinoma and its precursor lesions, whereas 17p LOH, mutation or loss of E-cadherin are more often implicated in the development of diffuse-type gastric cancer. In this review, we summarize the sometimes contradictory findings regarding those markers which influence the progression of gastric adenocarcinoma.

Molecular analysis of gastric differentiated-type intramucosal and submucosal cancers

Identification of the molecular characteristics of intramucosal (IMCs) and submucosal cancers (SMCs) is essential to our understanding of early gastric carcinogenesis. However, little is known regarding the differences between the 2 lesions. One hundred and forty-eight patients with primary early gastric cancer [IMC, 106; SMC, 42] were characterized for expression of cell cycle-related proteins and loss of heterozygosity (LOH). We also examined microsatellite instability (MSI) and methylation status. For LOH and methylation studies, we used a panel of 17 microsatellite markers (3p, 4p, 5q, 9p. 13q, 17p, 18q and 22q) and promoter regions of 9 genes (MLH-1, RUNX3, p16, HPP1, RASSF2A, SFRP1, DKK-1, ZFP64 and SALL4) that are frequently altered or methylated in gastric cancers. Overexpression of p53 and cyclin D1 was observed in SMC. In addition, low expression of p27 was more frequent in SMC than in IMC. Frequencies of 4p, 9p, 13q and 22q were significantly higher in SMC than in IMC. The SALL4 gene was frequently methylated in SMC compared with IMC. However, other gene methylations were common in both IMC and SMC. The frequency of LOH-high status/methylation-low status was significantly higher in SMC than in IMC. However, LOH-low status/methylation-high status in SMC was more frequently found in IMC. Our data confirm that methylation of cancer-related genes plays a major role in the development of IMCs. Importantly, the results also show that gastric submucosal progression is characterized by the accumulation of specific genetic alterations. In addition, changes of cell cycle-related proteins are associated with cancer progression.

Gastrin suppresses the interdependent expression of p16 and anion exchanger 1 favoring growth inhibition of gastric cancer cells

Our previous studies demonstrated that expression and interaction of p16 with anion exchanger 1 (AE1) in gastric cancer cells is correlated with progression and shorter survival of the cancer. In this article, the effects of gastrin on p16 and AE1 and its implication in prevention and treatment of gastric cancer were studied by molecular biology techniques, animal experiment and clinical analysis. The results showed that expression of p16 in human gastric body carcinoma was downregulated along with the progression of the cancer, suggesting the reverse correlations between gastrin and p16 in vivo. Further experiments indicated that gastrin suppressed the expression of p16 via the p16 promoter and thereafter resulted in the degradation of AE1 in gastric cancer cells. Silencing of AE1 or p16 significantly inhibited the proliferation of the cancer cells. Using a xenograft tumor model in nude mice, we showed that experimental systemic hypergastrinemia induced by the administration of omeprazole led to decreased expression of AE1 and p16 as well as to a marked growth inhibition of SGC7901 tumors. It is concluded that a moderate plasma gastrin level is beneficial to the growth inhibition of gastric cancer by suppressing the expression of AE1 and p16. This finding may have an important implication for the prevention and treatment of cancers arise in the gastric antrum.

Analysis of cell cycle-related proteins in gastric intramucosal differentiated-type cancers based on mucin phenotypes: a novel hypothesis of early gastric carcinogenesis based on mucin phenotype

Background

Abnormalities of cell cycle regulators are common features in human cancers, and several of these factors are associated with the early development of gastric cancers. However, recent studies have shown that gastric cancer tumorigenesis was characterized by mucin expression. Thus, expression patterns of cell cycle-related proteins were investigated in the early phase of differentiated-type gastric cancers to ascertain any mechanistic relationships with mucin phenotypes.

Methods

Immunostaining for Cyclins D1, A, E, and p21, p27, p53 and β-catenin was used to examine impairments of the cell cycle in 190 gastric intramucosal differentiated-type cancers. Mucin phenotypes were determined by the expressions of MUC5AC, MUC6, MUC2 and CD10. A Ki-67 positive rate (PR) was also examined.

Results

Overexpressions of p53, cyclin D1 and cyclin A were significantly more frequent in a gastric phenotype than an intestinal phenotype. Cyclin A was overexpressed in a mixed phenotype compared with an intestinal phenotype, while p27 overexpression was more frequent in an intestinal phenotype than in a mixed phenotype. Reduction of p21 was a common feature of the gastric intramucosal differentiated-type cancers examined.

Conclusions

Our results suggest that the levels of some cell cycle regulators appear to be associated with mucin phenotypes of early gastric differentiated-type cancers.

Evaluation of cell cycle protein expression in gastric cancer: cyclin B1 expression and its prognostic implication

The cell cycle progression is regulated by interactions of specific cyclin-dependent kinases at the G1-S and G2-M checkpoints. In addition, the cell cycle dysregulation plays a major role in carcinogenesis of human cancers. To investigate the role of cell cycle regulators in the pathogenesis and progression of human gastric cancer, the expression of cyclin D1, A, B1, p16(INK4a), p21(CPI1), p27(KIP1), p53, and pRb was investigated in 482 gastric carcinomas using immunohistochemistry in terms of histologic type, tumor invasion, size, location, and metastatic behavior. The cyclin D1, A, and B1 expression (>10%) was observed in 49%, 69%, and 49% of the cases, respectively. Negative cases for p16(INK4a), p21(CPI1), and p27(KIP1) were detected in 90%, 86%, and 50.5%. There were 30% and 68% of the gastric tumors positive for p53 and pRb, respectively. Diffuse carcinomas frequently were positive for cyclin B1 and pRb, and negative for p21. A relationship between p53 expression and intestinal type carcinomas was found. In addition, the expression of cyclin B1 was associated with regional lymph node metastasis and poor prognosis. No relationship was noticed between any other cell cycle proteins expression and age, sex, tumor size, tumor location, and lymph node involvement. These findings have shown alterations in several cell cycle regulators, and it was suggested that cyclin B1 expression is closely associated with poor behavior in gastric cancer.

Does the expression of cyclin E, pRb, and p21 correlate with prognosis in gastric adenocarcinoma?

BACKGROUND

Cyclin E is a protein that plays a key role in the G1 --> S transition of the normal cell cycle. The product of retinoblastoma gene (pRb) is the master regulator of entry into the cell cycle and p21 protein is a cyclin-dependent kinase inhibitor that disturbs the progression through the cell cycle. The expression of these proteins, among many others, is being deregulated in tumorogenesis. The aim of this study was to investigate whether cyclin E, pRb, and p21 can be used as prognostic indicators in gastric cancer.

MATERIAL AND METHODS

Fifty-six patients with gastric adenocarcinoma, who underwent curative resection, constituted the group of our study. The immunohistochemical expression of cyclin E, pRb, and p21 proteins was examined and correlated with clinical-pathological parameters and survival.

RESULTS

Positive cyclin E immunostaining was observed in 23 tumors (41.1%). It was associated with intestinal Lauren classification (P=0.003), nodal infiltration (P=0.0025), size of the tumor >5 cm (P=0.032), and lymphatic (P=0.042) and vascular invasion (P= 0.0029). Nevertheless, the survival of patients with positive cyclin E tumors was not significantly shorter than that of negative patients. Positive pRb immunostaining was found in 24 (42.9%) cases and it was associated with the absence of Helicobacter pylori (P=0.044), whereas positive p21 immunostaining was found in 21 tumors (37.5%) and it was associated with less depth of gastric wall infiltration (P=0.001), the absence of lymphatic (P=0.019) and vascular infiltration (P=0.024), and the absence of liver metastasis (P=0.044). Cyclin E expression was associated with pRb expression (P=0.023), but was correlated inversely with p21 expression (P=0.009). The survival of patients with pRb-positive tumors and the survival of patients with p21-positive tumors were significantly longer than that of negative patients (P= 0.0044 and P<0.001, respectively).

CONCLUSION

The expression of cyclin E could not predict the survival in this series of patients with gastric cancer, whereas the expression of pRb and p21 was associated with a favorable prognosis.

Abnormal expression of p16(INK4a), cyclin D1, cyclin-dependent kinase 4 and retinoblastoma protein in gastric carcinomas

BACKGROUND AND OBJECTIVES

The p16(INK4a) (p16), cyclin D1, cyclin-dependent kinase (CDK) 4 and retinoblastoma (Rb) genes are components of the Rb pathway that controls the G1-S checkpoint of the cell cycle. The aim of this study was to assess the relationship between their abnormalities and clinicopathological features in gastric carcinomas.

METHODS

Immunohistochemical analysis of the encoded proteins was performed on a series of 158 cases.

RESULTS

Loss of p16/Rb protein (pRb) expression and overexpression of cyclin D1/CDK4 were observed in 49%/40% and 37%/37% of gastric carcinomas, respectively. At least 1 of these abnormalities was found in 86% of the cases and a positive correlation was noted between p16 and pRb (P = 0.009). Cyclin D1 (P = 0.042) and CDK4 (P = 0.008) overexpession was inversely associated with lymph node metastasis and depth of invasion, respectively. Loss of pRb expression was more frequently in diffuse type lesions than in the intestinal type (P = 0.022). The patients with p16+/pRb-/cyclin D1-/CDK4- or p16-/pRb+/cyclin D1-/CDK4- tumors demonstrated particularly poor survival. With multivariate survival analysis, only depth of invasion and TNM stage could be proven as independent predictors.

CONCLUSIONS

The Rb pathway is disrupted in the vast majority of gastric carcinomas. This study also identified specific immunohistochemical marker profiles for prognosis.

Recent advances in conventional and molecular prognostic factors for gastric carcinoma

Despite radical surgery, the prognosis of patients who have gastric carcinoma remains unsatisfactory because of the intrinsic but unpredictable aggressiveness of this malignancy. During the past decade an ever-growing list of molecular prognostic factors has been proposed based on the discovery of the mechanisms underlying gastric cancer aggressiveness. Studies performed in larger and more homogeneous series of patients and adequate statistical analysis are warranted before any of the candidate biomarkers can be implemented in the routine clinical setting for the identification of patients at higher risk and thus for the selection of candidates for adjuvant or more aggressive therapies.

[Alterations of cell cycle regulating proteins: Rb, p21 and p16 in laryngeal cancer]

In cell cycle, most of the regulatory actions occur at the so-called restriction point (R) in the late G1 phase. Tumor suppressor genes; Rb, p53 and p21 are among the most important of the agents suppressing transition through R point. Changes in the expression of Rb (retinoblastoma) gene correlate with the presence of Rb protein and they are believed to be an early event in carcinogenesis. This issue seems to be not plainly defined in laryngeal cancer. P21 with p16, cyclin D1 and Rb genes that play a critical role in the regulation of the G1-S transition of the cell cycle, are frequently altered in several neoplastic entities. Our purpose was to investigate the possible prognostic value of p21, p16 and Rb proteins in patients with laryngeal cancer. 67 patients with laryngeal cancer was multi-variously analysed. Paraffin-embedded tissue sections were immunohistochemically stained with a monoclonal antibody raised against p21, p16 and Rb proteins using standard immunohistochemistry techniques. Low intensity (< or = 10%, 7/67) of p21 protein expression was significantly correlated with histological grading (p < 0,01) and overall and disease free survival (p < 0,05). We did not observed any correlation between p21 expression and T, N and M status and local or nodal recurrences. Absence of p16 protein expression was observed in 35/67 (52,2%) cases and was significantly correlated with N status (p = 0,03) and nodal recurrences (p = < 0,01). By univariate analysis expression of p16 protein was related with quicker relapse. Rb protein was absent in 7/67 cases (10,4%) and was related to T3 and T4 primary tumour size (p < 0,05). We did not observed any correlation between Rb and other clinocopathological features (p > 0,05). Our study has identified p21 protein expression as important biological marker which may indicate the progression of laryngeal squamous cell carcinoma. P16 protein has a prognostic value in assessment of disease free survival. Based on this findings it can be deduced that investigation of Rb, p16 and p21 proteins makes it easier to understand the process of cancerogenesis in laryngeal cancer and to establish its prognostic value further research and observations need to be attempted.

Interrelationships among chromosome aneuploidy, promoter hypermethylation, and protein expression of the CDKN2A gene in individuals from northern Brazil with gastric adenocarcinoma

Numerical alterations of chromosome 9, the status of promoter methylation and protein expression of the CDKN2A gene (aliases include p16 and p16(INK4a)), the possible association with gain of chromosome X, and the interrelation of these findings with clinic and pathological characteristics were investigated in gastric adenocarcinomas. Fluorescence in situ hybridization analysis with centromeric DNA probes, immunohistochemical staining, and methylation-specific polymerase chain reaction assays were performed in 15 gastric adenocarcinomas samples from individuals from northern Brazil. Aneuploidies of chromosomes X and 9 were found in all samples, both intestinal and diffuse type. Monosomy of chromosome 9 and gain of a copy of chromosome X (in both sexes) were observed in 100% of cases. Hypermethylation frequency and protein expression of CDKN2A were also found in all cases analyzed. No association of genetic and epigenetic alterations with histological type, tumor aggressiveness, and invasion was found (P > 0.05), which may be attributable to small sample size. There was a high level of association between absence of p16 protein expression levels, CDKN2A gene promote hypermethylation, and chromosome 9 aneuploidy (100% of cases). Thus, in the present samples, the apparent mechanisms behind p16 silencing include loss of chromosome 9 and promoter region hypermethylation.

Protein expression profiling and molecular classification of gastric cancer by the tissue array method

PURPOSE

Gastric cancer is heterogeneous clinically and histologically, and prognosis prediction by tumor grade or type is difficult. Although previous studies have suggested that frozen tissue-based molecular classifications effectively predict prognosis, prognostic classification on formalin-fixed tissue is needed, especially in early gastric cancer.

EXPERIMENTAL DESIGN

We immunostained 659 consecutive gastric cancers using 56 tumor-associated antibodies and the tissue array method. Hierarchical cluster analyses were done before and after feature selection. To optimize classifier number and prediction accuracy for prognosis, a supervised analysis using a support vector machine algorithm was used.

RESULTS

Of 56 gene products, 27 survival-associated proteins were selected (feature selection), and hierarchical clustering identified two clusters: cluster 1 and cluster 2. Cluster 1 cancers were more likely to have intestinal type, earlier stage, and better prognosis than cluster 2 (P<0.05). In 187 early gastric cancers (pT1), cluster 2 was associated with the presence of metastatic lymph nodes (P=0.026). Kaplan-Meier survival curves stratified by pathologic tumor-lymph node metastasis revealed that cluster 2 was associated with poor prognosis in stage I or II cancer (P<0.05). Support vector machines and genetic algorithms selected nine classifiers from the whole data set, another nine classifiers for stage I and II, and eight classifiers for stage III and IV. The prediction accuracies for patient outcome were 73.1%, 88.1%, and 76%, respectively.

CONCLUSIONS

Protein expression profiling using the tissue array method provided a useful means for the molecular classification of gastric cancer into survival-predictive subgroups. The molecular classification predicted lymph node metastasis and prognosis in early stage gastric cancer.

Carcinogenic hypergastrinemia: signet-ring cell carcinoma in a patient with multiple endocrine neoplasia type 1 with Zollinger-Ellison's syndrome

CONTEXT

Gastric neuroendocrine tumors are rare neoplasms that originate from gastric enterochromaffin-like (ECL) cells in the oxyntic mucosa. Gastrin and its derivates have been reported to regulate epithelial cell proliferation, migration, and differentiation. Mutations in the epithelial cadherin (E-cadherin) gene have been shown to be associated with the occurrence of diffuse gastric carcinomas in affected families.

OBJECTIVE

In this study we investigated the histopathological and molecular findings in the gastrointestinal wall of a patient with multiple endocrine neoplasia type 1 with malignant duodenal gastrinoma and multiple gastric ECL cell tumors, who additionally developed a signet-ring cell carcinoma of the stomach.

DESIGN AND PATIENT

Biopsies from the gastrointestinal tract of a patient with multiple endocrine neoplasia type 1 were immunostained for vesicular monoamine transporter-2 and E-cadherin. Nonamidated gastrin products were measured in the serum of the patient using antibodies that react with progastrin, Gly-extended, and amidated gastrins. Genetic analyses were performed to exclude germ-line mutations within the E-cadherin gene.

RESULTS

Immunohistochemical studies of gastric ECL cell tumors showed a largely diminished E-cadherin expression in comparison to gastric surface mucosa cells and a loss of E-cadherin expression in the cells of the signet-ring carcinoma. Detailed biochemical measurements revealed progastrin concentrations that were approximately 20%, and Gly-gastrin concentrations that were approximately 10% the amidated gastrin concentrations in plasma. Molecular analyses revealed no E-cadherin germ-line mutation.

CONCLUSION

Our immunohistochemical studies might suggest that the gastrinoma-associated excessive progastrin tissue concentrations led to diminished expression of E-cadherin within the gastric mucosa and promoted tumor development of a signet-ring cell carcinoma.

Evaluation of malignant and benign gastric biopsy specimens by mRNA expression profile and multivariate statistical methods

BACKGROUND

mRNA expression array and multivariate statistical analysis of gastric biopsies can yield insight into the molecular biology basis of local alterations, supporting expression-based identification of morphological alterations.

METHODS

From 11 patients with erosive gastritis(EG), 5 with adenocarcinoma (GC), 11 with atrophic gastritis (AG) gastric biopsies were collected, total RNA isolated, T7 amplification and expression analysis of 1047 mRNAs was performed using commercial glass arrays (Clontech, USA). After microarray quality control, applicable data were available from 7 EG, 4 GC, and 5 AG. Multivariate statistical and cell functional analysis were performed. Real-time RT-PCR and immunohistochemistry were used for validation.

RESULTS

GC was characterized by overregulated v-raf, v-erb-a, BCL2-associated- athanogene, immediate-early-response-3, Polo-like kinase, CDK-2, cyclin-C, Pin1 genes, and downregulated ADP-ribosyltransferase, sialophorin and DCC. AG cases had increased PDGF-receptor, TGF-beta-receptor-3, and decreased death-associated-protein-3, beta-1-catenin, topoisomerase-1 levels. In EG upregulation of IGF-receptor-1, CD9, transferrin receptor, integrins, and underexpression of keratin-5, caspase-4 was found. Discriminant analysis could reclassify all samples correctly using four parameters.

CONCLUSIONS

mRNA expression array analysis of gastric biopsies yields previously known and new data in the evaluation of local gastric alterations.

Antibody detection using tumor-associated antigen mini-array in immunodiagnosing human hepatocellular carcinoma

BACKGROUND/AIMS

Previous studies have demonstrated that during transition from chronic liver disease to hepatocellular carcinoma (HCC), autoantibodies can appear which are not detected in the prior pre-malignant conditions. These antibody responses may be stimulated by cellular proteins involved in carcinogenesis. This study determines the prevalence of antibodies to a selected panel of eight tumor-associated antigens (TAAs) in sera from patients with chronic hepatitis, liver cirrhosis and HCC, and considers the possibility and usefulness of antibodies to such a panel of TAAs in differentiating between these conditions. The panel of eight TAAs includes Imp1, p62, Koc, p53, c-myc, cyclin B1, survivin and p16 full-length recombinant proteins.

METHODS

Enzyme-linked immunosorbent assay (ELISA) was used to detect antibodies against eight selected TAAs in 30 sera from chronic hepatitis, 30 from liver cirrhosis, and 142 from HCC. Positive results were also confirmed by slot blot, Western blotting and immunoprecipitation assay.

RESULTS

Antibody frequency to any individual TAA in HCC varied from 9.9% to 21.8%. With the successive addition of TAAs to a final total of eight antigens, there was a stepwise increase of positive antibody reactions reaching a frequency of 59.8% with whole cohort of HCC patients. This was significantly higher than the frequency of antibodies in chronic hepatitis (20%), liver cirrhosis (30%) and normal individuals (12.2%).

CONCLUSIONS

This study demonstrates that malignant transition to HCC is associated with increased autoantibody responses to certain cellular proteins which might have a role in tumorigenesis, and shows that a mini-array of eight TAAs enhanced antibody detection for diagnosis of HCC. More studies in patients with HCC and precursor conditions such as chronic hepatitis, alcoholic hepatitis and liver cirrhosis using enlarged TAA mini-array panels might further improve the sensitivity and specificity of this mode of cancer immunodiagnosis. Its additional usefulness might be in the early detection of cancer in some patients with predisposing conditions.

RB family members as predictive and prognostic factors in human cancer

The retinoblastoma family members--pRb, pRb2/p130 and p107--are tumor suppressor genes involved in controlling four major cellular processes: growth arrest, apoptosis, differentiation and angiogenesis. Molecular genetic studies have identified abnormalities of these tumor suppressor genes in a large proportion of human cancers. These genetic alterations have emerged as significant factors in the pathogenesis and progression of many types of tumors and are therefore likely to provide relevant information to assess risk in cancer patients. There is a pressing clinical need to identify prognostic and predictive factors for patients with cancer, because there is an undeniable importance in being able to determine which patients will have a favorable outcome without further therapy (prognostic factor) and which will need some additional treatment (predictive factor). This review examines the predictive and/or prognostic role of each retinoblastoma family member in human cancer.

p16INK4a immunoexpression: surrogate marker of high-risk HPV and high-grade cervical intraepithelial neoplasia

p16INK4a has emerged as a valuable surrogate marker for high-risk human papillomavirus infection and shows increased immunoexpression with worsening grades of cervical intraepithelial neoplasia (CIN). Numerous studies have emerged in recent years supporting its role in the detection of high-grade dysplasia and have lead to the use of p16INK4a immunohistochemistry in many laboratories. However, only a few studies have examined the possible predictive or prognostic value of p16INK4a in CIN or cervical cancer. This review addresses some of the practical issues in the application of p16INK4a in everyday practice, with an emphasis on integrating the extensive data that have emerged in the literature on p16INK4a immunoreactivity in CIN. The potential role of p16INK4a immunohistochemistry in the prediction of CIN progression is also discussed.

Mechanisms for Helicobacter pylori CagA-induced cyclin D1 expression that affect cell cycle

Particular Helicobacter pylori genotypes differentially induce epithelial cell proliferation, but the mechanisms are not characterized. We explored the effect of H. pylori CagA on expression of cyclin D1, an important cell cycle regulator. H. pylori-induced cell survival and cyclin D1 expression were attenuated in a cagA mutant. AP1 and cAMP response element (CRE), but not NF-kappaB, were involved in the induced cyclin D1 expression. Diminished mitogen-activated protein kinase (MAPK) activation, especially involving p38, with downstream effects on AP1 and CRE activation, was observed for the cagA mutant. In total, these data show that cagA+ H. pylori strains are enhanced in their ability to activate MAPKs and downstream transcription factors, increasing cyclin D1 expression, G1-S phase progression, and host cell survival, explaining both the preferential survival of affected host cells, and the enhanced oncogenesis by these bacteria.

Alterations of the CCND1 and HER-2/neu (ERBB2) proteins in esophageal and gastric cancers

We evaluated the relationship of amplification and polysomy of both the CCND1 and the ERBB2 (alias HER-2/NEU) genes to the overexpression of their proteins in esophageal and gastric cancers and also their association with clinicopathological features. CCND1 gene amplification (45%) was more prevalent than polysomy (25%) in esophageal carcinoma, but the pattern observed was similar in gastric adenocarcinoma (10% amplification, 15% polysomy). For ERBB2, polysomy was a more frequent mechanism than amplification in both esophageal (32.5 vs. 7.5%) and gastric (15 vs. 5%) cancers. Overexpression of cyclin D1 protein was identified in 37.5% of the specimens of esophageal tumors and 35% of gastric tumors, and overexpression of Her-2/neu protein in 12.5 and 7.5%, respectively. The kappa-statistics revealed a fair agreement in both types of tumors only in overexpression and amplification of the CCND1 gene; the ERBB2 gene showed a fair agreement in amplification and polysomy and the level of protein expression in gastric adenocarcinoma. Thus, polysomy 17 could contribute to a high Her-2/neu protein level, at least in gastric cancer. Our data indicated an association with alcohol consumption and the CCND1 gene or protein levels, in both esophageal and gastric cancers.

Down-expression of tumor protein p53-induced nuclear protein 1 in human gastric cancer

AIM: Overexpression of tumor protein p53-induced nuclear protein 1 (TP53INP1) induces G₁ cell cycle arrest and increases p53-mediated apoptosis. To clarify the clinical importance of TP53INP1, we analyzed TP53INP1 and p53 expression in gastric cancer.

METHODS: TP53INP1 and p53 expression were examined using immunohistochemistry in 142 cases of gastric cancer. The apoptosis of gastric cancer cells was analyzed using the TUNEL method. The relationship between the expression of TP53INP1 and clinicopathological factors was statistically analyzed.

RESULTS: TP53INP1 was expressed in 98% (139/142 cases) of non-cancerous gastric tissues and was down-expressed in 64% (91/142 cases) of gastric cancer lesions from the same patients. TP53INP1 expression was significantly decreased (43.9%) in poorly differentiated adenocarcinoma compared with well or moderately differentiated adenocarcinoma (81.6%). Cancers invading the submucosa or deeper showed lower positively (59.1%) compared with mucosal cancers (85.2%). Decrease or loss of TP53INP1 expression was significantly correlated with lymphatic invasion (54.3% vs 82.0% without lymphatic invasion) and node-positive patients (31.3% vs 68.3% in node-negative patients). P53 was expressed in 68 (47.9%) patients of gastric cancer, whereas it was absent in normal gastric tissues. A significant association was also observed between TP53INP1 status and the level of apoptosis in tumor cells: the apoptotic index in TP53INP1-positive tissues was significantly higher than that in TP53INP1-negative portions. Finally, when survival data were analyzed, loss of TP53INP1 expression had a significant effect in predicting a poor prognosis (P = 0.0006).

CONCLUSION: TP53INP1-positive rate decreases with the progression of gastric cancer. TP53INP1 protein negativity is significantly associated with aggressive pathological phenotypes of gastric cancer. TP53INP1 is related to the apoptosis of gastric cancer cells. The decreased expression of the TP53INP1 protein may reflect the malignant grade of gastric cancer and is regarded as an adverse prognostic factor.

ADAM23, a possible tumor suppressor gene, is frequently silenced in gastric cancers by homozygous deletion or aberrant promoter hypermethylation

Array-based comparative genomic hybridization (CGH-array) has a powerful potential for high-throughput identification of genetic aberrations in cell genomes. We identified a homozygous loss of ADAM23 (2q33.3) in the course of a program to screen a panel of gastric cancer (GC) cell lines (1/32, 3.1%) for genomic copy-number aberrations using our custom-made CGH-array. Infrequent homozygous deletion of ADAM23 was also seen in primary gastric tumors (1/39, 2.6%). ADAM23 mRNA was expressed in normal stomach tissue, but not in the majority of GC cell lines without homozygous deletion of this gene. Expression of ADAM23 mRNA was restored to gene-silenced GC cells after treatment with 5-aza 2'-deoxycytidine. The methylation status of the ADAM23 CpG island, which showed promoter activity, correlated inversely with its expression. Methylation of this CpG island was observed both in GC cell lines and in primary GC tissues; in primary tumors with a hypermethylated CpG island, expression of ADAM23 was lower than in adjacent noncancerous tissues. Moreover, restoration of ADAM23 in GC cells reduced their numbers in colony-formation assays. These results suggest that genetic or epigenetic silencing by hypermethylation of the ADAM23 CpG-rich promoter region leads to loss of ADAM23 function, which may be a factor in gastric carcinogenesis.