Detection of gastric carcinoma-associated MG7-Ag by serum immuno-PCR assay in a high-risk Chinese population, with implication for screening

Chinese integrated guideline on the management of gastric precancerous conditions and lesions

The standardized diagnosis and management of gastric precancerous conditions and lesions are important to prevent gastric cancer. This guideline, created by 5 traditional Chinese medicine and Western medicine associations, based on the current morbidity and diagnosis and treatment of gastric precancerous conditions and lesions, provides specific key points and strategies for diagnosis and treatment in the following five aspects: definition and epidemiology, diagnosis and stage, surveillance, treatment and efficacy evaluation. It is hoped that these aspects, assessed by integrating Western medicine and traditional Chinese medicine and involving multidisciplinary participation, will play a guiding role in clinical diagnosis and treatment and achieve effective secondary prevention of gastric cancer.

PGC-MG7 combination could be used as a follow-up panel for monitoring dynamical progression of gastric precancerous diseases

Objective

The aim of this study was to investigate the value of the combined expression of the gastric mucosal differentiation protein pepsinogen C (PGC) and gastric cancer (GC)-associated antigen MG7 for the diagnosis of GC and prediction of the development from precancerous conditions to GC.

Methods

The gastric mucosal biopsies of 285 subjects enrolled from a region with a high incidence of GC were obtained and histopathologically examined. Subjects testing negative for GC (n=208) were followed up from 1998 to 2015. The levels of PGC and MG7 in the biopsies were determined by immunohistochemistry.

Results

PGC was positive in 91.4% of the non-atrophic gastritis, 26.5% of the atrophic gastritis, and 0% of the GC. MG7 was positive in 15.0% of the non-atrophic gastritis, 82.4% of the atrophic gastritis, and 94.8% of the GC. The non-atrophic gastritis group was predominantly “PGC+MG7−”. The atrophic gastritis and GC groups were predominantly “PGC−MG7+”. The rate of GC in subjects with “PGC−MG7+” staining was 113.4-fold higher [95% confidence interval (95% CI): 15.3−869.4, P<0.001] than that in subjects with other staining patterns. The sensitivity and specificity of the “PGC−MG7+” pattern were 92.2% and 78.8% for the detection of GC and 77.2% and 97.9% for GC and precancerous disease, respectively. In the follow-up cohort of non-GC subjects, the risk of developing GC was higher in those with the “PGC−MG7+” staining pattern.

Conclusions

Our data suggest that the “PGC−MG7+” pattern can be employed as a useful follow-up panel for detecting individuals with a high risk of GC, and the dynamic assessment of the follow-up panel needs multi-centre large-scale validation in the future.

The contribution of platelets to intravascular arrest, extravasation, and outgrowth of disseminated tumor cells

Platelets are primarily known for their contribution to hemostasis and subsequent wound healing. In addition to these functions, platelets play a role in the process of metastasis. Since the first study that suggested a metastasis-promoting function for platelets was published in 1968, various mechanisms have been proposed to explain how platelets contribute to the metastatic process. These include roles in the intravascular arrest of tumor cells, in tumor cell transendothelial migration, in the degradation of basement membrane barriers, in migration and invasion at the metastatic site, and in the proliferation of disseminated tumor cells. Nevertheless, conflicting observations about the role of platelets in these processes have also been reported. Here, we review the in vivo evidence that supports a role for platelets in metastasis formation, propose several scenarios for the contribution of platelets to tumor cell arrest and transendothelial migration, and discuss the evidence that platelets contribute to metastatic invasion and outgrowth.

Detection of potential biomarkers associated with outrageous diseases and environmental pollutants by nanoparticle-based immuno-PCR assays

Immuno-polymerase chain reaction (I-PCR) assay with advantages of both enzyme-linked immunosorbent assay (ELISA) and PCR exhibits several-fold enhanced sensitivity in comparison to respective ELISA, which has wide applications for ultralow detection of several molecules, i.e. cytokines, protooncogenes and biomarkers associated with several diseases. Conjugation of reporter DNA to the detection antibodies is the most crucial step of I-PCR assay that usually employs streptavidin-protein A, streptavidin-biotin conjugate or succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) system by a covalent binding. However, coupling of antibodies and oligonucleotides to nanoparticles (NPs) is relatively easier in the NP-based I-PCR (NP-I-PCR) that also displays better accuracy. This article is mainly focused on the detection of important biomarkers associated with several outrageous infectious and non-infectious diseases by NP-I-PCR assays, which would expedite an early initiation of therapy thus human health would be improved. Similarly, ultralow detection of environmental pollutants by these assays and their elimination would certainly improve human health.

[Advances in serum biomarkers for early diagnosis of gastric cancer]

Early diagnosis is the key to improve the prognosis of gastric cancer. How to screen out high-risk subjects of gastric cancer in population is a hot spot. Serum-based early detection of gastric cancer is suitable for high-risk population screening, which is more convenient and safer. This article reviews the diagnostic value of serum biomarkers for gastric cancer, including serum DNA methylation, various RNAs, pepsinogen, gastrin, osteopontin, MG7-Ag and CA724. Until now, there is still lack of ideal biomarkers for gastric cancer, and searching for specific RNAs may be promising for early diagnosis and screening of gastric cancer.

Invadopodia are chemosensing protrusions that guide cancer cell extravasation to promote brain tropism in metastasis

Invadopodia are cell protrusions that mediate cancer cell extravasation but the microenvironmental cues and signaling factors that induce invadopodia formation during extravasation remain unclear. Using intravital imaging and loss of function experiments, we determined invadopodia contain receptors involved in chemotaxis, namely GABA receptor and EGFR. These chemotaxis capabilities are mediated in part by PAK1 which controls invadopodia responsiveness to ligands such as GABA and EGF via assembly, stability, and turnover of invadopodia in vivo. PAK1 knockdown rendered cells unresponsive to chemotactic stimuli present in the stroma, resulting in dramatically lower rates of cancer cell extravasation and metastatic colony formation compared to stimulated cancer cells. In an experimental mouse model of brain metastasis, inhibition of PAK1 significantly reduced overall tumor burden and reduced the average size of brain metastases. In summary, invadopodia contain chemotaxis receptors that can respond to microenvironmental cues to guide cancer cell extravasation, and when PAK1 is depleted, brain tropism of metastatic breast cancer cells is significantly reduced, blocking secondary colony growth at sites otherwise permissive for metastatic outgrowth.

Isolated pancreatic metastases from renal cell carcinoma: an outcome of a special metastatic pathway or of specific tumor cell selection?

Isolated pancreatic metastases (isPM) are a rare metastasizing pattern in the natural history of renal cell cancer. Their clinical hallmark is that they are confined to a single organ, the pancreas, while all other organs are unaffected for a long time. Almost all workers in the field suggested that mechanical tumor cell propagation to the pancreas may be the mechanism underlying this metastasizing pattern. In 2006 our group, by contrast, proposed an alternative mechanism, i.e. a special affinity of the tumor cells for the pancreas. In the present study an attempt was made to shed more light on the settlement of isPM by reviewing recent literature data. 666 observations of isPM reported in the literature were reviewed. The analyses showed that local lymphatic spread does not play a major role because the lymphatic system is, in general, rarely involved in isPM. This also applies to a local venous spread, because the site of pancreatic metastases is independent of the side affected by the primary renal cancer. But the results are compatible with a systemic metastatic pathway. That metastases in other organs, which would be expected given a systemic spread, are absent can plausibly be explained by a seed and soil mechanism: only the pancreas offers the tumor cell emboli an environment which is conducive to the growth of clinically manifest metastases, while settlement of metastatic tumor cells is prevented in all other organs.

Precise targeting of cancer metastasis using multi-ligand nanoparticles incorporating four different ligands

Metastasis displays a highly heterogeneous cellular population with cancer cells continuously evolving. As a result, a single-ligand nanoparticle cannot account for the continuously changing expression of targetable biomarkers over time and space. To effectively direct nanoparticles to metastasis, we developed a multi-ligand nanoparticle by using four different types of ligands on the same nanoparticle that target biomarkers on the endothelium associated with metastatic disease. These vascular targets included αvβ3 integrin, P-selectin, EGFR and fibronectin. Using terminal and in vivo imaging studies, the targeting performance of the multi-ligand nanoparticles was compared to the single-ligand nanoparticle variants. All four single-ligand nanoparticle variants achieved significant targeting of lung metastasis in the 4T1 mouse model of breast cancer metastasis with about 2.5% of the injected dose being deposited into metastasis. A dual-ligand nanoparticle resulted in a nearly 2-fold higher deposition into lung metastases than its single-ligand counterparts. The multi-ligand nanoparticle significantly outperformed its targeting nanoparticle counterparts achieving a deposition of ∼7% of its injected nanoparticles into lung metastases. Using the high sensitivity of radionuclide imaging, PET imaging showed that a multi-ligand nanoparticle labeled with [18F]fluoride was able to precisely target metastatic disease at its very early stage of development in three different animal models of metastatic breast cancer.

Three-dimensional combined biomarkers assay could improve diagnostic accuracy for gastric cancer

So far, stomach-specific biomarkers, gastric cancer(GC)-related environmental factors, and cancer-associated biomarkers are three major classes of serological biomarkers with GC warning potential, joint detection of which is expected to increase the diagnosis efficiency. We investigated whether the combination of serum pepsinogens(PGs), IgG anti-Helicobacter pylori (HpAb), and osteopontin (OPN) can be used as a panel for GC diagnose. Serum was collected from 365 GC patients and 729 healthy individuals,furtherly 332 cases and 332 age- and sex-matched controls were selected for the matched analysis. Serum levels were measured by ELISA. Logistic regression and receiver operator characteristic curve (ROC) were used to assess the associations of biomarkers with GC and the discriminative performance of biomarkers for GC. The area under ROC from three-dimensional combination of PGI/II-HpAb-OPN (0.826) was significantly higher than two-dimensional combination of PGI/II-HpAb (0.786, P < 0.001), PGI/II-OPN (0.787, P < 0.001), and OPN-HpAb (0.801, P = 0.006), as well as one-biomarker of PGI/II (0.735, P < 0.001), HpAb (0.737, P < 0.001) and OPN(0.713, P < 0.001), respectively. The combination of PGI/II-HpAb-OPN, yielded a sensitivity of 70.2% and specificity of 78.3% at the predicted probability of 0.493 as the optimal cutoff point. Three-dimensional combined biomarkers assay could improve diagnostic accuracy for gastric cancer.

A global burden of gastric cancer: the major impact of China

Gastric cancer (GC) is a highly aggressive cancer and a major cause of cancer-related deaths worldwide. Approximately half of the world's GC cases and deaths occur in china. GC presents challenges in early diagnosis and effective therapy due to a lack of understanding of the underlying molecular biology. The primary goals of this review are to outline current GC research in china and describe future trends in this field. Areas covered: This review mainly focuses on a series of GC-related advances China has achieved. Considerable progress has been made in understanding the role of H. pylori in GC by a series of population-based studies in well-established high-risk areas; A few germline and somatic alterations have been identified by 'omics' studies; Studies on the mechanisms of malignant phenotypes have helped us to form an in-depth understanding of GC and advance drug discovery. Moreover, identification of potential biomarkers and targeted therapies have facilitated the diagnosis and treatment of GC. However, many challenges remain. Expert commentary: To combat GC, sufficient funding is important. More attention should be paid on early diagnosis and the discovery of novel efficient biomarkers and the development of biomarker-based or targeted therapeutics in GC.

BIIB021: A novel inhibitor to heat shock protein 90–addicted oncology

Heat shock protein 90 is induced in response to the cell stress. Its overexpression has been reported in many cancers with poor prognosis. It acts as a chaperone to the client proteins, especially the activated oncoproteins in malignancies to protect them from degradation. Heat shock protein 90 inhibition represented anti-cancer effects in many studies. Previous natural product–based compounds are limited by their association with target toxicities. BIIB021 is an orally available, fully synthetic novel small-molecule heat shock protein 90 inhibitor that has shown strong antitumor activities in a large number of preclinical models and is now under clinical investigation. This review will summarize its therapeutic effects and highlight the prospect of targeting heat shock protein 90 in the cancer therapy.

Elevated amino acids in gastric juice as potential biomarkers for gastric cancer

Early diagnosis plays a vital role in the improvement of the curative rate of gastric cancer. However, the poor specificity and sensitivity of traditional gastric cancer biomarkers, such as carcino-embryonic antigen and carbohydrate antigen 199, make it difficult to screen early gastric cancer. Gastric juice amino acid profile may be an alternative tumor marker, since abnormal elevation of amino acids in gastric juice has been reported in precancerous patients. Normal concentration of amino acids is extremely low in gastric juice, and special techniques are required to detect amino acids in gastric juice. The change of amino acids in gastric juice is more significant than in blood and tumor tissue. The amino acid profile in gastric juice may work as efficient biomarkers for gastric cancer with the development of amino acid detection technique.

Immuno-PCR in cancer and non-cancer related diseases: a review

Polymerase chain reaction-amplified immunoassay (immuno-PCR, iPCR) is a method that combines the specificity of an immunological detection method and the sensitivity of a nucleic acid amplification method. In this way, immuno-PCR uses a minimum amount of sample, and allows the detection of rare diseases and those diseases in very early stage (i.e. infectious diseases, degenerative disorders, or neoplastic diseases). The present review was aimed to describe this new methodology and applications to the early detection of cancer and non-cancer related diseases, and discuss about the possibility to detect diverse biomarkers of oncology disorders, such as breast, gastric, colorectal and nasopharynx cancer, and other factors related to the growth of the neoplastic disease.

P-glycoprotein confers acquired resistance to 17-DMAG in lung cancers with an ALK rearrangement

BACKGROUND

Because anaplastic lymphoma kinase (ALK) is dependent on Hsp90 for protein stability, Hsp90 inhibitors are effective in controlling growth of lung cancer cells with ALK rearrangement. We investigated the mechanism of acquired resistance to 17-(Dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG), a geldanamycin analogue Hsp90 inhibitor, in H3122 and H2228 non-small cell lung cancer cell lines with ALK rearrangement.

METHODS

Resistant cell lines (H3122/DR-1, H3122/DR-2 and H2228/DR) were established by repeated exposure to increasing concentrations of 17-DMAG. Mechanisms for resistance by either NAD(P)H/quinone oxidoreductase 1 (NQO1), previously known as a factor related to 17-DMAG resistance, or P-glycoprotein (P-gp; ABCB1/MDR1) were queried using RT-PCR, western blot analysis, chemical inhibitors, the MTT cell proliferation/survival assay, and cellular efflux of rhodamine 123.

RESULTS

The resistant cells showed no cross-resistance to AUY922 or ALK inhibitors, suggesting that ALK dependency persists in cells with acquired resistance to 17-DMAG. Although expression of NQO1 was decreased in H3122/DR-1 and H3122/DR-2, NQO1 inhibition by dicumarol did not affect the response of parental cells (H2228 and H3122) to 17-DMAG. Interestingly, all resistant cells showed the induction of P-gp at the protein and RNA levels, which was associated with an increased efflux of the P-gp substrate rhodamine 123 (Rho123). Transfection with siRNA directed against P-gp or treatment with verapamil, an inhibitor of P-gp, restored the sensitivity to the drug in all cells with acquired resistance to 17-DMAG. Furthermore, we also observed that the growth-inhibitory effect of 17-DMAG was decreased in A549/PR and H460/PR cells generated to over-express P-gp by long-term exposure to paclitaxel, and these cells recovered their sensitivity to 17-DMAG through the inhibition of P-gp.

CONCLUSION

P-gp over-expression is a possible mechanism of acquired resistance to 17-DMAG in cells with ALK rearrangement.

Conjugation of toll-like receptor-7 agonist to gastric cancer antigen MG7-Ag exerts antitumor effects

AIM: To investigate the effects of our tumor vaccines on reversing immune tolerance and generating therapeutic response.

METHODS: Vaccines were synthesized by solid phase using an Fmoc strategy, where a small molecule toll-like receptor-7 agonist (T7) was conjugated to a monoclonal gastric cancer 7 antigen mono-epitope (T7-MG1) or tri-epitope (T7-MG3). Cytokines were measured in both mouse bone marrow dendritic cells and mouse spleen lymphocytes after exposed to the vaccines. BALB/c mice were intraperitoneally immunized with the vaccines every 2 wk for a total of three times, and then subcutaneously challenged with Ehrlich ascites carcinoma (EAC) cells. Three weeks later, the mice were killed, and the tumors were surgically removed and weighed. Serum samples were collected from the mice, and antibody titers were determined by ELISA using an alkaline phosphate-conjugated detection antibody for total IgG. Antibody-dependent cell-mediated cytotoxicity was detected by the lactate dehydrogenase method using natural killer cells as effectors and antibody-labeled EAC cells as targets. Cytotoxic T lymphocyte activities were also detected by the lactate dehydrogenase method using lymphocytes as effectors and EAC cells as targets.

RESULTS: Vaccines were successfully synthesized and validated by analytical high performance liquid chromatography and electrospray mass spectrometry, including T7, T7-MG1, and T7-MG3. Rapid inductions of tumor necrosis factor-α and interleukin-12 in bone marrow dendritic cells and interferon γ and interleukin-12 in lymphocytes occurred in vitro after T7, T7-MG1, and T7-MG3 treatment. Immunization with T7-MG3 reduced the EAC tumor burden in BALB/c mice to 62.64% ± 5.55% compared with PBS control (P < 0.01). Six or nine weeks after the first immunization, the monoclonal gastric cancer 7 antigen antibody increased significantly in the T7-MG3 group compared with the PBS control (P < 0.01). As for antibody-dependent cell-mediated cytotoxicity, antisera obtained by immunization with T7-MG3 were able to markedly enhance cell lysis compared to PBS control (31.58% ± 2.94% vs 18.02% ± 2.26%; P < 0.01). As for cytotoxic T lymphocytes, T7-MG3 exhibited obviously greater cytotoxicity compared with PBS control (40.92% ± 4.38% vs 16.29% ± 1.90%; P < 0.01).

CONCLUSION: A successful method is confirmed for the design of gastric cancer vaccines by chemical conjugation of T7 and multi-repeat-epitope of monoclonal gastric cancer 7 antigen.

Immunomodulatory drugs target IKZF1-IRF4-MYC axis in primary effusion lymphoma in a cereblon-dependent manner and display synergistic cytotoxicity with BRD4 inhibitors

Primary effusion lymphoma (PEL) is an aggressive type of non-Hodgkin lymphoma localized predominantly in body cavities. Kaposi’s sarcoma-associated herpes virus is the causative agent of PEL. PEL is an incurable malignancy and has extremely poor prognosis when treated with conventional chemotherapy. Immunomodulatory drugs (IMiDs) lenalidomide and pomalidomide are FDA approved drugs for the treatment of various ailments. IMiDs display pronounced anti-proliferative effect against majority of PEL cell lines within their clinically achievable concentrations, by arresting cells at G₀/G₁ phase of cell-cycle, and without any induction of KSHV lytic-cycle reactivation. Although microarray examination of PEL cells treated with lenalidomide revealed activation of interferon (IFN) signaling, blocking the IFN pathway did not block the anti-PEL activity of IMiDs. The anti-PEL effects of IMiDs involved cereblon-dependent suppression of IRF4 and rapid degradation of IKZF1, but not IKZF3. Small hairpin-RNA (shRNA) mediated knockdown of MYC enhanced the cytotoxicity of IMiDs. Bromodomain and extraterminal domain (BET) proteins are epigenetic readers which perform a vital role in chromatin remodeling and transcriptional regulation. BRD4, a widely expressed transcriptional coactivator, belongs to BET family of proteins, which has been shown to co-occupy the super-enhancers associated with MYC. Specific BRD4 inhibitors were developed which suppress MYC transcriptionally. Lenalidomide displayed synergistic cytotoxicity with several structurally distinct BRD4 inhibitors (JQ-1, IBET151, and PFI-1). Furthermore, combined administration of lenalidomide and BRD4 inhibitor JQ-1 significantly increased the survival of PEL bearing NOD.SCID mice in an orthotopic xenograft model as compared to either agent alone. These results provide compelling evidence for clinical testing of IMiDs alone and in combination with BRD4 inhibitors for PEL.

Proximity assays for sensitive quantification of proteins

Proximity assays are immunohistochemical tools that utilise two or more DNA-tagged aptamers or antibodies binding in close proximity to the same protein or protein complex. Amplification by PCR or isothermal methods and hybridisation of a labelled probe to its DNA target generates a signal that enables sensitive and robust detection of proteins, protein modifications or protein-protein interactions. Assays can be carried out in homogeneous or solid phase formats and in situ assays can visualise single protein molecules or complexes with high spatial accuracy. These properties highlight the potential of proximity assays in research, diagnostic, pharmacological and many other applications that require sensitive, specific and accurate assessments of protein expression.

Application of GFP imaging in cancer

Multicolored proteins have allowed the color-coding of cancer cells growing in vivo and enabled the distinction of host from tumor with single-cell resolution. Non-invasive imaging with fluorescent proteins enabled the dynamics of metastatic cancer to be followed in real time in individual animals. Non-invasive imaging of cancer cells expressing fluorescent proteins has allowed the real-time determination of efficacy of candidate antitumor and antimetastatic agents in mouse models. The use of fluorescent proteins to differentially label cancer cells in the nucleus and cytoplasm can visualize the nuclear-cytoplasmic dynamics of cancer cells in vivo including: mitosis, apoptosis, cell-cycle position, and differential behavior of nucleus and cytoplasm that occurs during cancer-cell deformation and extravasation. Recent applications of the technology described here include linking fluorescent proteins with cell-cycle-specific proteins such that the cells change color from red to green as they transit from G1 to S phases. With the macro- and micro-imaging technologies described here, essentially any in vivo process can be imaged, giving rise to the new field of in vivo cell biology using fluorescent proteins.

The diagnostic value of monoclonal gastric cancer 7 antigen: a systematic review with meta-analysis

The aim of this study is to explore the clinical characteristic and the diagnostic role of MG7-Ag in detecting gastric cancer (GC) through a systematic review and meta-analysis. Relevant manuscripts aiming at the application of serum MG7-Ag level in GC diagnosis were searched in PubMed, Embase, Chinese National Knowledge Infrastructure, VIP, and Wan Fang Data independently,which were published between January 1, 1980 and February 28, 2013. The pooled sensitivity, specificity,positive diagnostic likelihood ratio (DLR+), negative diagnostic likelihood ratio (DLR-), diagnostic odds ratio,and the area under the summary receiver operating characteristic(AUC) were used to evaluate the value of serum MG7-Ag in diagnosis of GC by using the Meta-DiSc and STATA 11.0 statistical software. 410 manuscripts were retrieved, and 7 manuscripts of high quality including 652 patients were of high quality in this meta-analysis. Overall,the pooled sensitivity, specificity, DLR+, DLR-, and AUC were 0.73 (95 % CI 0.63-0.82), 0.91 (95 % CI 0.84-0.94), 8.59 (95 % CI 5.62-13.11), 0.29 (95 % CI 0.21-0.42), and 0.92 (95 % CI 0.89-0.94), respectively. MG7-Ag is a potential biomarker for the diagnosis of GC.However, more studies are needed to confirm the standard criteria.

Protein chaperones: a composition of matter review (2008 - 2013)

INTRODUCTION

Heat shock proteins (Hsps) are proteins with important functions in regulating disease phenotypes. Historically, Hsp90 has first received recognition as a target in cancer, with consequent efforts extending its potential role to other diseases. Hsp70 has also attracted interest as a therapeutic target for its role as a co-chaperone to Hsp90 as well as its own anti-apoptotic roles.

AREAS COVERED

Herein, patents from 2008 to 2013 are reviewed to identify those that disclose composition of matter claimed to inhibit Hsp90 or Hsp70.

EXPERT OPINION

For Hsp90, there has been considerable creativity in the discovery of novel pharmacophores that fall outside the three initially discovered scaffolds (i.e., ansamycins, resorcinols and purines). Nonetheless, much of the patent literature appears to build on previously reported structure activity relationship through slight modifications of Hsp90 inhibitor space by finding weaknesses in existing patents. The major goal of future development of Hsp90 inhibitors is not necessarily identifying better molecules but rather understanding how to rationally use these agents in the clinic. The development of Hsp70 inhibitors has lagged behind. It will require a more concerted effort from the drug discovery community in order to begin to realize the potential of this target.

Implementation of gastric cancer screening - the global experience

Gastric cancer (GC) is still an important global healthcare problem, and in absolute figures it is going to remain at the present level in foreseeable future. In general, survival of patients with GC is poor mainly due to advanced-stage diagnosis. Early-stage GC can be cured by endoscopic resection or less invasive surgical treatment. Unfortunately, there is no appropriate screening strategy available for global application. This article provides a description of established national and regional GC screening programs and the screening modalities used. This review also summarizes current approaches to develop cancer-screening biomarkers. Although candidates with initial promising results have been suggested, moving discovery into clinical practice is still a major challenge. Well-designed biomarker studies, with systematic validation steps, are needed to decrease the burden of this fatal disease.

Hsp90 inhibitor BIIB021 enhances triptolide-induced apoptosis of human T-cell acute lymphoblastic leukemia cells in vitro mainly by disrupting p53-MDM2 balance

AIM

To investigate the effects of BIIB021, an inhibitor of heat shock protein 90 (Hsp90) alone or in combination with triptolide (TPL) on T-cell acute lymphoblastic leukemia (T-ALL) and the mechanisms of action.

METHODS

Human T-ALL cells line Molt-4 was examined. The cell viability was measured using MTT assay. Apoptotic cells were studied with Hoechst 33258 staining. Cell apoptosis and cell cycle were analyzed using flow cytometry with Annexin V/PI staining and PI staining, respectively. The levels of multiple proteins, including Akt, p65, CDK4/6, p18, Bcl-2 family proteins, MDM2, and p53, were examined with Western blotting. The level of MDM2 mRNA was determined using RT-PCR.

RESULTS

Treatment of Molt-4 cells with BIIB021 (50-800 nmol/L) inhibited the cell growth in a dose-dependent manner (the IC50 value was 384.6 and 301.8 nmol/L, respectively, at 48 and 72 h). BIIB021 dose-dependently induced G0/G1 phase arrest, followed by apoptosis of Molt-4 cells. Furthermore, BIIB021 increased the expression of p18, decreased the expression of CDK4/6, and activated the caspase pathway in Molt-4 cells. Moreover, BIIB021 (50-400 nmol/L) dose-dependently decreased the phospho-MDM2 and total MDM2 protein levels, but slightly increased the phospho-p53 and total p53 protein levels, whereas TPL (5-40 nmol/L) dose-dependently enhanced p53 activation without affecting MDM2 levels. Co-treatment with BIIB021 and TPL showed synergic inhibition on Molt-4 cell growth. The co-treatment disrupted p53-MDM2 balance, thus markedly enhanced p53 activation. In addition, the co-treatment increased the expression of Bak and Bim, followed by increased activation of caspase-9.

CONCLUSION

The combination of BIIB021 and TPL may provide a novel strategy for treating T-ALL by overcoming multiple mechanisms of apoptosis resistance.

A survey and evaluation of population-based screening for gastric cancer

Screening and early diagnosis of gastric cancer play important roles in reducing the mortality of gastric cancer. A vast amount of study data on gastric cancer screening and early diagnosis has been accumulated in and out of China in the past decades. The practice of gastric cancer screening has also been efficiently carried out in different countries and regions. However, no widely accepted principle of population screening for gastric cancer has been developed yet. Screening for gastric cancer requires extensive exploration both theoretically and practically. This article focuses on the method and program of gastric cancer screening based on population. Moreover, the current situation of gastric cancer screening and its evaluation are evaluated.

While at Rome miRNA and TRAIL do whatever BCR-ABL commands to do

It is a well-acclaimed fact that proteins expressed as a consequence of oncogenic fusions, mutations or amplifications can facilitate ectopic protein-protein interactions that re-wire signal dissemination pathways, in a manner that escalates malignancy. BCR-ABL-mediated signal transduction cascades in leukemic cells are assembled and modulated by a finely controlled network of protein-protein interactions, mediated by characteristic signaling domains and their respective binding motifs. BCR-ABL functions in a cell context-specific and cell type-specific manner to integrate signals that affect uncontrolled cellular proliferation. In this review, we draw attention to the recent progress made in outlining resistance against TRAIL-mediated apoptosis and diametrically opposed roles of miRNAs in BCR-ABL-positive leukemic cells. BCR-ABL governs carcinogenesis through well-organized web of antiapoptotic proteins and over-expressed oncomirs which target death receptors and pro-apoptotic genes. Set of oncomirs which inversely correlate with expression of TRAIL via suppression of SMAD is an important dimension which is gradually gaining attention of the researchers. Contrary to this, some current findings show a new role of BCR-ABL in nucleus with spotlight on apoptosis. It seems obvious that genetic heterogeneity of leukemias poses therapeutic challenges, and pharmacological agents that target components of the cancer promoting nano-machinery still need broad experimental validation to be considered competent as a component of the therapeutic arsenal for this group of diseases. Rapidly developing technologies are empowering us to explain the molecular "nature" of a patient and/or tumor and with this integration of personalized medicine, with maximized efficacy, cost effectiveness will hopefully improve survival chances of the patient.

Heat shock proteins in cancer: targeting the 'chaperones'

Heat shock proteins (Hsps) are highly conserved proteins working as molecular chaperones for several cellular proteins essential for normal cell viability and growth, and have numerous cytoprotective roles. The expression of Hsps is induced in response to a wide variety of physiological and environmental stress insults, including anticancer chemotherapy, thus allowing the cell to survive lethal conditions. Cancer cells experience high levels of proteotoxic stress and rely upon stress-response pathways for survival and proliferation, thereby becoming dependent on proteins such as stress-inducible Hsps. Owing to the implication of Hsps in cancer, Hsp inhibition has recently emerged as an interesting potential anticancer strategy. Many natural and synthetic Hsp inhibitors molecular compounds are in development and many are being evaluated as potential cancer therapies. One of the Hsps in particular, Hsp90, has several client proteins and is emerging as a particularly exciting cancer target due to the prospect of simultaneously inhibiting chaperoning of numerous oncogenic proteins. This review describes the function of Hsps focusing on current efforts in exploiting the attributes of Hsps as potential targets for anticancer therapy.

Conditioned medium from bone marrow mesenchymal stem cells transiently retards osteoblast differentiation by downregulating runx2

Mesenchymal stem cells (MSCs) are attractive candidates for cell therapy and regenerative medicine because of their potential for proliferation and multilineage differentiation. MSCs secrete various cytokines, acting as trophic mediators to regulate neighboring cells. Osteoblasts are the cells directly responsible for forming new bone, and they are the final target of many osteogenic regulators. However, the induction effect of MSCs on osteoblasts is still unknown. In this study, we isolated osteoblasts from rat calvariae and investigated their proliferation and differentiation under induction of varied concentrations of MSC-conditioned medium (MSC-CM). Cells in the MSC-CM groups showed a reduction in cell proliferation at 3-6 days, and a decrease in the expression of osteocalcin and osteopontin at 3 days, with low levels of alkaline phosphatase activity. The expression of osteogenic markers went back to normal at 7 days. In order to evaluate the molecular mechanisms underlying this suppression, levels of two osteoblastic transcription factors, runt-related transcription factor 2 (Runx2) and osterix (Osx), were detected at both mRNA and protein levels. The results indicated that MSC-CM significantly inhibited Runx2 expression in a concentration-dependent manner. However, the effect was not due to the inhibition of Osx, for Osx was not significantly altered. This work demonstrates that MSCs may suppress osteoblast proliferation and transiently retard osteoblast differentiation by downregulating Runx2. These results highlight the need to take into account the paracrine effect of MSCs when using them in regenerative medicine for the repair of bone defects.

Molecular basis for the actions of Hsp90 inhibitors and cancer therapy

Heat-shock protein 90 (Hsp90) inhibitor downregulates c-Myc expression and upregulates the expression of tumor repressor proteins such as p53 and pRB, inhibiting the G1/S transition and causing G2/M arrest during cell cycle progression. The cycle progression is extensively controlled by the pRB/E2F signaling pathway. E2F is released from the pRB/E2F complex with the phosphorylation of pRB by cyclin-cyclin-dependent kinase (CDK) complexes. The released E2F promotes the transcription of target genes involved in cell cycle progression. The pRB/E2F signaling pathway is controlled by DNA methyltransferase-1 (Dnmt-1). The elevated expression of Dnmt-1 has been reported in carcinomas of the colon, lung and prostate. A defect of pRB expression in Rb -/- cancer cells is caused by the aberrant methylation of CpG in the Rb promoter. The Hsp90 inhibitor disrupts the Dnmt-1/Hsp90 association and upregulates pRB expression. In this review, the Hsp90 inhibitors that show promise for cancer therapy are summarized.

Serum pepsinogen II: a neglected but useful biomarker to differentiate between diseased and normal stomachs

BACKGROUND AND AIM

Serum pepsinogen II (sPGII) is underutilized and considered an inconspicuous biomarker in clinical practice. We refocused on this neglected but novel biomarker and conducted the present study, aiming to elucidate the normal level of sPGII in healthy Chinese patients and to investigate the clinical utility of sPGII for gastric disease screening.

METHODS

In 2008-2009, a total of 2022 participants from northern China were selected and enrolled in the study. sPGII and Helicobacter pylori (H. pylori)-immunoglobulin G were measured with ELISA.

RESULTS

sPGII showed a normal value of 6.6 microg/L in a total of 466 patients with endoscopically- and histologically-normal stomachs. A small sex difference was observed: the average value of sPGII was 7 microg/L and 6 microg/L in males and females, respectively (P < 0.001). In the differentiation between healthy and diseased (endoscopically-diseased stomach or gastritis/atrophic gastritis in endoscopic biopsies) stomach mucosae, the best sPGII cut-off value was 8.25 microg/L (sensitivity 70.6%, specificity 70.8%). In screening the H. pylori seropositivity, the optimum cut-off sPGII value was 10.25 microg/L (sensitivity 71.6%, specificity 70.1%).

CONCLUSIONS

We demonstrated that the mean values of sPGII in a healthy Chinese population are 7 microg/L and 6 microg/L for males and females, respectively. sPGII significantly increases in diseased and H. pylori-infected stomach, and the best sPGII cut-off value is 8.25 microg/L in the differentiation between patients with healthy and diseased stomach mucosae. Furthermore, Chinese patients with sPGII greater than 10.25 microg/L are at greater risk of various H. pylori-related gastropathies, and are therefore prior candidates for gastro-protection therapy.

SP1 suppresses phorbol 12-myristate 13-acetate induced up-regulation of human regucalcin expression in liver cancer cells

There is a growing evidence that regucalcin (RGN) plays a multifunctional role in liver cancer cells. Previous reports showed that the presence of phorbol 12-myristate 13-acetate (PMA) caused a significant increase in RGN mRNA expression and promoter activity in rat hepatoma cells. In this study, we confirmed that human RGN is also up-regulated by PMA treatment independent of translation, and we identified the mechanism by which PMA up-regulates the expression of human RGN via driving SP1 away from a SP1 motif located within -188/-180 of the promoter in HepG2 cells. Overexpression of SP1 dramatically reduces PMA-induced up-regulation of both internal expression of mRNA and promoter activity, whereas knockdown of SP1 has the opposite effect. Therefore, the present study delineates the fundamental elements in the promoter which will be helpful in the future studies on the regulation of RGN expression in liver cancer.

The value of MG7-Ag and COX-2 for predicting malignancy in gastric precancerous lesions

Here we aimed to first investigate the clinical value of combined detection of MG7-Ag and COX-2 (cyclo-oxygenase 2) in prediction of advances in gastric precancerous lesions. Immunohistochemical analysis was used to examine the expression of MG7-Ag and COX-2 in 396 cases of patients with gastric precancerous lesions, including 66 cases of atrophic gastritis, 106 cases of intestinal metaplasia, 174 cases of low-moderate-grade dysplasia and 50 cases of high-grade dysplasia. The relation of MG7-Ag and COX-2 staining with various clinicopathological features was analysed by follow-up study. The positive rates of MG7-Ag and COX-2 were increased gradually from atrophic gastritis (21.2%, 28.8%), intestinal metaplasia (36.8%, 44.3%), low-moderate-grade dysplasia (51.4%, 58.6%) to high-grade dysplasia (72%, 80%). Double positive staining of MG7-Ag and COX-2 in gastric precancerous lesions had an increased risk of precancerous progression over 22 times, compared with negative ones. However, the expression of MG7-Ag and COX-2 was not significantly correlated with age and gender of patients. MG7-Ag and COX-2 might play an important role in the process of carcinogenesis and progression of gastric cancer. Combined detection of MG7-Ag and COX-2 was of value of predicting early gastric cancer from precancerous lesions.