MEKK3 expression correlates with nuclear factor kappa B activity and with expression of antiapoptotic genes in serous ovarian carcinoma

Clinical Significance and Regulation of ERK5 Expression and Function in Cancer

Extracellular signal-regulated kinase 5 (ERK5) is a unique kinase among MAPKs family members, given its large structure characterized by the presence of a unique C-terminal domain. Despite increasing data demonstrating the relevance of the ERK5 pathway in the growth, survival, and differentiation of normal cells, ERK5 has recently attracted the attention of several research groups given its relevance in inflammatory disorders and cancer. Accumulating evidence reported its role in tumor initiation and progression. In this review, we explore the gene expression profile of ERK5 among cancers correlated with its clinical impact, as well as the prognostic value of ERK5 and pERK5 expression levels in tumors. We also summarize the importance of ERK5 in the maintenance of a cancer stem-like phenotype and explore the major known contributions of ERK5 in the tumor-associated microenvironment. Moreover, although several questions are still open concerning ERK5 molecular regulation, different ERK5 isoforms derived from the alternative splicing process are also described, highlighting the potential clinical relevance of targeting ERK5 pathways.

CircSETDB1 knockdown inhibits the malignant progression of serous ovarian cancer through miR-129-3p-dependent regulation of MAP3K3

Background

Circular RNA (circRNA) is recently found to participate in the regulation of tumor progression, including ovarian cancer. However, the application of circRNA SET domain bifurcated histone lysine methyltransferase 1 (circSETDB1) as a therapeutic target in serous ovarian cancer (SOC) remains to be elucidated. Herein, circSETDB1 role in SOC malignant progression and underlying mechanism are revealed.

Methods

The expression of circSETDB1, microRNA-129-3p (miR-129-3p) and mitogen-activated protein kinase kinase kinase 3 (MAP3K3) messenger RNA (mRNA) was detected by quantitative real-time polymerase chain reaction. Protein abundance was determined by western blot analysis. Cell proliferation, apoptosis, invasion and migration were demonstrated by cell counting kit-8 and 5-Ethynyl-29-deoxyuridine assays, flow cytometry analysis, transwell invasion assay and wound-healing assay, respectively. The interaction between miR-129-3p and circSETDB1 or MAP3K3 was predicted by online database, and identified by mechanism assays. The effect of circSETDB1 knockdown on tumor formation in vivo was unveiled by mouse model experiment.

Results

CircSETDB1 and MAP3K3 expression were apparently upregulated, whereas miR-129-3p expression was downregulated in SOC tissues and cells in comparison with normal fallopian tube tissues or normal ovarian epithelial cells. CircSETDB1 knockdown inhibited cell proliferation, invasion and migration, but induced cell apoptosis in SOC cells. Additionally, miR-129-3p inhibitor impaired circSETDB1 silencing-mediated SOC malignant progression. MiR-129-3p repressed SOC cell processes via binding to MAP3K3. Furthermore, circSETDB1 knockdown suppressed tumor growth in vivo.

Conclusion

CircSETDB1 silencing repressed SOC malignant progression through miR-129-3p/MAP3K3 pathway. This study supports circSETDB1 as a new therapeutic target for SOC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00875-0.

1. CircSETDB1 expression was increased in SOC tissues and cells.

2. CircSETDB1 silencing repressed the malignancy of SOC cells.

3. CircSETDB1 mediated SOC malignant progression by interacting with miR-129-3p.

4. MAP3K3 served as a target gene of miR-129-3p.

5. CircSETDB1 knockdown inhibited tumor formation in vivo.

MEKK3 in hybrid snakehead (Channa maculate ♀ ×Channa argus ♂): Molecular characterization and immune response to infection with Nocardia seriolae and Aeromonas schubertii

Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is a serine/threonine protein kinase that acts as a key regulator and is widely involved in various innate and acquired immune signaling pathways. In this study, we first cloned the complete open reading frame (ORF) of the MEKK3 gene (named CcMEKK3) in a hybrid snakehead (Channa maculate ♀ × Channa argus ♂). The full-length ORF of CcMEKK3 is 1851 bp, and encodes a putative protein of 616 amino acids containing a serine/threonine kinase catalytic (S-TKc) domain and a Phox and Bem1p (PB1) domain. A sequence alignment and phylogenetic tree analysis showed that CcMEKK3 is highly conserved relative to the MEKK3 proteins of other teleost species. CcMEKK3 was constitutively expressed in all the healthy hybrid snakehead tissues tested, with greatest expression in the immune tissues, such as the head kidney and spleen. The expression of CcMEKK3 was usually upregulated in the head kidney, spleen, and liver at different time points after infection with Nocardia seriolae or Aeromonas schubertii. Similarly, the dynamic expression levels of CcMEKK3 in head kidney leukocytes after stimulation revealed that CcMEKK3 was induced by LTA, LPS, and poly(I:C). In the subcellular localization analysis, CcMEKK3 was evenly distributed in the cytoplasm of HEK293T cells, and its overexpression significantly promoted the activities of NF-κB and AP-1. These results suggest that CcMEKK3 is involved in the immune defense against these two pathogens, and plays a crucial role in activating the NF-κB and MAPK signaling pathways.

DNM3OS Facilitates Ovarian Cancer Progression by Regulating miR-193a-3p/MAP3K3 Axis

PURPOSE

Long non-coding RNAs (lncRNAs) are essential regulators in the development of ovarian cancer (OC). Nonetheless, the function of lncRNA DNM3 opposite strand/antisense RNA (DNM3OS) in OC remains unclear. This work aimed to investigate the biological roles and underlying mechanisms of DNM3OS in OC.

MATERIALS AND METHODS

Quantitative real-time polymerase chain reaction was conducted to examine DNM3OS, microRNA (miR)-193a-3p, and mitogen-activated protein kinase 3 (MAP3K3) mRNA expression in OC tissues and cell lines. Kaplan-Meier survival analysis was employed to analyze the relationship between DNM3OS expression and the prognosis of OC patients. Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and transwell experiments were conducted to monitor cell proliferation, migration, and invasion, respectively. Western blot was applied to examine epithelial-mesenchymal transition associated protein (E-cadherin and N-cadherin) expression. Luciferase reporter gene and RNA immunoprecipitation experiments were performed to confirm the relationships among DNM3OS, miR-193a-3p, and MAP3K3. Pearson's correlation analysis was adopted to analyze the correlations among DNM3OS, miR-193a-3p, and MAP3K3 mRNA.

RESULTS

DNM3OS expression was remarkably increased in OC tissues and cell lines, which was associated with the unfavorable prognosis of the patients. DNM3OS overexpression enhanced OC cell proliferation, migration, and invasion; suppressed E-cadherin protein expression; and facilitated N-cadherin protein expression, while the transfection of miR-193a-3p mimics had the opposite effects. DNM3OS directly interacted with miR-193a-3p, and miR-193a-3p targeted MAP3K3 by directly binding to 3'UTR. DNM3OS could up-regulate the expression of MAP3K3 via repressing miR-193a-3p expression.

CONCLUSION

DNM3OS, as an oncogenic lncRNA, increases the malignancy of OC cells via regulation of an miR-193a-3p/MAP3K3 axis.

Protein Kinase-Mediated Decision Between the Life and Death

Protein kinases are intracellular signaling enzymes that catalyze the phosphorylation of specific residues in their target substrate proteins. They play important role for regulation of life and death decisions. The complexity of the relationship between death receptors and protein kinases' cell death decision-making mechanisms create many difficulties in the treatment of various diseases. The most of fifteen different cell death pathways, which are reported by Nomenclature Committee on Cell Death (NCCD) are protein kinase signal transduction-mediated negative or positive selections. Tumor necrosis factor (TNF) as a main player of death pathways is a dual-functioning molecule in that it can promote both cell survival or cell death. All apoptotic and necrotic signal transductions are conveyed through death domain-containing death receptors, which are expressed on the surface of nearly all human cells. In humans, eight members of the death receptor family have been identified. While the interaction of TNF with TNF Receptor 1 (TNFR1) activates various signal transduction pathways, different death receptors activate three main signal transduction pathways: nuclear factor kappa B (NF-ĸB)-mediated differentiation or pro-inflammatory cytokine synthesis, mitogen-activated protein kinase (MAPK)-mediated stress response and caspase-mediated apoptosis. The link between the NF-ĸB and the c-Jun NH₂-terminal kinase (JNK) pathways comprise another check-point to regulate cell death. TNF-α also promotes the "receptor-interacting serine/threonine protein kinase 1" (RIPK1)/RIPK3/ mixed lineage kinase domain-like pseudokinase (MLKL)-dependent necrosis. Thus, necrosome is mainly comprised of MLKL, RIPK3 and, in some cases, RIPK1. In fact, RIPK1 is at the crossroad between life and death, downstream of various receptors as a regulator of endoplasmic reticulum stress-induced death. TNFR1 signaling complex (TNF-RSC), which contains multiple kinase activities, promotes phosphorylation of transforming growth factor β-activated kinase 1 (TAK1), inhibitor of nuclear transcription factor κB (IκB) kinase (IKK) α/IKKβ, IκBα, and NF-κB. IKKs affect cell-survival pathways in NF-κB-independent manner. Toll-like receptor (TLR) stimulation triggers various signaling pathways dependent on myeloid differentiation factor-88 (MyD88), Interleukin-1 receptor (IL-1R)-associated kinase (IRAK1), IRAK2 and IRAK4, lead to post-translational activation of nucleotide and oligomerization domain (NLRP3). Thereby, cell fate decisions following TLR signaling is parallel with death receptor signaling. Inhibition of IKKα/IKKβ or its upstream activators sensitize cells to death by inducing RIPK1-dependent apoptosis or necroptosis. During apoptosis, several kinases of the NF-κB pathway, including IKK1 and NF-κB essential modulator (NEMO), are cleaved by cellular caspases. This event can terminate the NF-κB-derived survival signals. In both canonical and non-canonical pathways, IKK is key to NF-κB activation. Whereas, the activation process of IKK, the functions of NEMO ubiquitination, IKK-related non-canonical pathway and the nuclear transportation of NEMO and functions of IKKα are still debated in cell death. In addition, cluster of differentiation 95 (CD95)-mediated non-apoptotic signaling and CD95- death-inducing signaling complex (DISC) interactions are waiting for clarification.

NF-κB Signaling in Ovarian Cancer

The NF-κB signaling pathway is a master and commander in ovarian cancer (OC) that promotes chemoresistance, cancer stem cell maintenance, metastasis and immune evasion. Many signaling pathways are dysregulated in OC and can activate NF-κB signaling through canonical or non-canonical pathways which have both overlapping and distinct roles in tumor progression. The activation of canonical NF-κB signaling has been well established for anti-apoptotic and immunomodulatory functions in response to the tumor microenvironment and the non-canonical pathway in cancer stem cell maintenance and tumor re-initiation. NF-κB activity in OC cells helps to create an immune-evasive environment and to attract infiltrating immune cells with tumor-promoting phenotypes, which in turn, drive constitutive NF-κB activation in OC cells to promote cell survival and metastasis. For these reasons, NF-κB is an attractive target in OC, but current strategies are limited and broad inhibition of this major signaling pathway in normal physiological and immunological functions may produce unwanted side effects. There are some promising pre-clinical outcomes from developing research to target and inhibit NF-κB only in the tumor-reinitiating cancer cell population of OC and concurrently activate canonical NF-κB signaling in immune cells to promote anti-tumor immunity.

Overexpression of MAP3K3 promotes tumour growth through activation of the NF-κB signalling pathway in ovarian carcinoma

Mitogen-activated protein kinase kinase kinase 3 (MAP3K3), a member of the serine/threonine protein kinase family, is ubiquitously expressed and acts as an oncogene. However, the expression and exact molecular mechanism of MAP3K3 in ovarian carcinoma (OC) remain unclear. Here, we found that MAP3K3 protein was highly expressed in 70.5% of high-grade serous ovarian carcinoma (HGSOC) samples. MAP3K3 overexpression was significantly associated with the FIGO stage and chemotherapy response. Additionally, MAP3K3 overexpression was associated with reduced disease-free survival and overall survival. In vitro experiments showed that MAP3K3 overexpression promoted cell proliferation, inhibited apoptosis, and enhanced the migration and invasion of OC cells. Moreover, in vivo tumourigenesis experiments confirmed that silencing MAP3K3 significantly reduced the growth rate and volume of transplanted tumours in nude mice. Drug sensitivity experiments demonstrated that differential expression of MAP3K3 in OC cell lines correlates with chemotherapy resistance. Functionally, the MAP3K3 gene regulated the malignant biological behaviour of OC cells by mediating NF-κB signalling pathways, affecting the downstream epithelial-mesenchymal transition and cytoskeletal protein expression. Our results unveiled the role of MAP3K3 in mediating NF-κB signalling to promote the proliferation, invasion, migration, and chemotherapeutic resistance of OC cells, highlighting a potential new therapeutic and prognostic target.

miR‑505 inhibits cell growth and EMT by targeting MAP3K3 through the AKT‑NFκB pathway in NSCLC cells

MicroRNAs (miRNAs) are short non-coding RNAs, which generally regulate gene expression at the post-transcriptional level. Dysregulation of miRNAs has been reported in numerous cancer types, including lung cancer. In the present study, the role of miR-505 in non-small cell lung cancer (NSCLC) cells was investigated. miR-505 served a tumor suppressor role in NSCLC cells. By reverse transcriptase-quantitative polymerase chain reaction detection, it was demonstrated that miR-505 was downregulated in NSCLC tissues and cell lines, which is negatively associated with large tumor size, Tumor-Node-Metastasis stage and distant metastasis in patients with NSCLC. Functional studies revealed that miR-505 inhibited cell proliferation, migration, invasion and epithelial-mesenchymal transition progress in vitro and tumor growth in vivo. Mechanically, mitogen-activated protein kinase kinase kinase 3 (MAP3K3) was identified as a direct target of miR-505 by binding to its 3′untranslated region and demonstrated to mediate the tumor suppressor roles of miR-505 in NSCLC cells. The effect of miR-505 on the activation of AKT/nuclear factor-κB (NFκB) pathway, which was downstream targets of MAP3K3, was further analyzed by western blot analysis and immunofluorescence analyses. The data demonstrated the inhibition of the AKT/NFκB pathway upon overexpressing miR-505 and the activation of AKT/NFκB pathway upon silencing miR-505. Collectively, the data revealed the novel role and target of miR-505 in NSCLC cells, which may provide novel insights regarding its role in the carcinogenesis of NSCLC and its potential values for clinical applications.

Oncogenic signaling of MEK5-ERK5

Mitogen-activated protein kinases (MAPKs) regulate diverse cellular processes including proliferation, cell survival, differentiation, and apoptosis. While conventional MAPK constituents have well-defined roles in oncogenesis, the MEK5 pathway has only recently emerged in cancer research. In this review, we consider the MEK5 signaling cascade, focusing specifically on its involvement in drug resistance and regulation of aggressive cancer phenotypes. Moreover, we explore the role of MEK5/ERK5 in tumorigenesis and metastatic progression, discussing the discrepancies in preclinical studies and assessing its viability as a therapeutic target for anti-cancer agents.

Microbial Degradation of Cellular Kinases Impairs Innate Immune Signaling and Paracrine TNFα Responses

The NFκB and MAPK signaling pathways are critical components of innate immunity that orchestrate appropriate immune responses to control and eradicate pathogens. Their activation results in the induction of proinflammatory mediators, such as TNFα a potent bioactive molecule commonly secreted by recruited inflammatory cells, allowing for paracrine signaling at the site of an infection. In this study we identified a novel mechanism by which the opportunistic pathogen Porphyromonas gingivalis dampens innate immune responses by disruption of kinase signaling and degradation of inflammatory mediators. The intracellular immune kinases RIPK1, TAK1, and AKT were selectively degraded by the P. gingivalis lysine-specific gingipain (Kgp) in human endothelial cells, which correlated with dysregulated innate immune signaling. Kgp was also observed to attenuate endothelial responsiveness to TNFα, resulting in a reduction in signal flux through AKT, ERK and NFκB pathways, as well as a decrease in downstream proinflammatory mRNA induction of cytokines, chemokines and adhesion molecules. A deficiency in Kgp activity negated decreases to host cell kinase protein levels and responsiveness to TNFα. Given the essential role of kinase signaling in immune responses, these findings highlight a unique mechanism of pathogen-induced immune dysregulation through inhibition of cell activation, paracrine signaling, and dampened cellular proinflammatory responses.

Inhibition of nuclear factor-kappa B enhances the tumor growth of ovarian cancer cell line derived from a low-grade papillary serous carcinoma in p53-independent pathway

Background

NF-kB can function as an oncogene or tumor suppressor depending on cancer types. The role of NF-kB in low-grade serous ovarian cancer, however, has never been tested. We sought to elucidate the function of NF-kB in the low-grade serous ovarian cancer.

Methods

The ovarian cancer cell line, HOC-7, derived from a low-grade papillary serous carcinoma. Introduction of a dominant negative mutant, IkBαM, which resulted in decrease of NF-kB function in ovarian cancer cell lines. The transcription ability, tumorigenesis, cell proliferation and apoptosis were observed in derivative cell lines in comparison with parental cells.

Results

Western blot analysis indicated increased expression of the anti-apoptotic proteins Bcl-xL and reduced expression of the pro-apoptotic proteins Bax, Bad, and Bid in HOC-7/IĸBαM cell. Further investigations validate this conclusion in KRAS wildtype cell line SKOV3. Interesting, NF-kB can exert its pro-apoptotic effect by activating mitogen-activated protein kinase (MAPK) phosphorylation in SKOV3 ovarian cancer cell, whereas opposite changes detected in p-MEK in HOC-7 ovarian cancer cell, the same as some chemoresistant ovarian cancer cell lines. In vivo animal assay performed on BALB/athymic mice showed that injection of HOC-7 induced subcutaneous tumor growth, which was completely regressed within 7 weeks. In comparison, HOC-7/IĸBαM cells caused sustained tumor growth and abrogated tumor regression, suggesting that knock-down of NF-kB by IĸBαM promoted sustained tumor growth and delayed tumor regression in HOC-7 cells.

Conclusion

Our results demonstrated that NF-kB may function as a tumor suppressor by facilitating regression of low grade ovarian serous carcinoma through activating pro-apoptotic pathways.

MAP3K3 overexpression is associated with poor survival in ovarian carcinoma

Mitogen-activated protein kinase kinase kinase 3 (MAP3K3) is ubiquitously expressed in numerous tissues and is activated by various extracellular stimuli to regulate processes, such as cell proliferation and differentiation. Recent studies have identified potentially pathologic conditions of MAP3K3 as an oncogene that promotes tumor progression and metastasis in a number of malignancies. However, the clinical significance of MAP3K3 expression in ovarian carcinoma (OC) remains unclear. In this study, the correlation between MAP3K3 expression and OC prognosis was assessed by immunohistochemistry. MAP3K3 overexpression was observed in 59.1% (55/93) of OCs and was significantly associated with histological type and grade, chemotherapy response, and challenge model (P < .05, respectively). MAP3K3 overexpression was also used as an independent prognostic marker for decreased disease-free survival and overall survival. In OC cell lines, MAP3K3 expression was evaluated by Western blot analysis, quantitative real-time polymerase chain reaction, and immunofluorescence. High MAP3K3 expression is significantly detected in SKOV3, C13*, and A2780 cells. All these findings suggested that MAP3K3 overexpression is an independent poor prognostic indicator of OC and can be a clinically effective biomarker of OC.

Crosstalk between the TNF and IGF pathways enhances NF-κB activation and signaling in cancer cells

BACKGROUND

The receptor for type I insulin like growth factor (IGF-IR) and NFκB signaling both play essential roles in cancer initiation and progression but relatively little is known about possible crosstalk between these pathways. We have shown that the IGF-IR could rescue lung and colon carcinoma cells from Tumor necrosis factor -α (ΤΝF-α)-induced apoptosis by activating autocrine, pro-survival IL-6/gp130/STAT3 signaling, suggesting that IGF-IR expression could alter NF-κB signaling that is required for transcriptional activation of IL-6.

OBJECTIVE

Here we sought to determine if and how IGF-IR signaling promotes TNF-α-induced NFκB activation.

DESIGN

We used lung carcinoma M-27 and colon carcinoma MC-38 cells to investigate IGF-IR-induced changes to the IKK/IκBα/NFκB pathway by a combination of qPCR, Western blotting, electrophoretic mobility shift assay, a reporter assay and gene silencing.

RESULTS

We show that in the presence of increased IGF-IR expression or activation levels, nuclear translocation of NFκB in response to TNF-α was enhanced in lung and colon carcinoma cells and this was due to accelerated phosphorylation and degradation of IκBα. This effect was AKT-dependent and mediated via mitogen-activated protein kinase kinase kinase 3(MEKK3) activation.

CONCLUSION

The results suggest that ligand-mediated activation of IGF-IR alters NF-κB signaling in cancer cells in an AKT/MEKK3-dependent manner and that temporal aspects of NF-κB activation can regulate the cytokine profile of the tumor cells and thereby, their interaction with the microenvironment.

MAP3K3 expression in tumor cells and tumor-infiltrating lymphocytes is correlated with favorable patient survival in lung cancer

MAP3K3 is involved in both the immune response and in tumor progression. Its potential biological role in vitro in lung cancer cell lines and the association of mRNA/protein expression patterns with clinical outcome of primary lung tumors were investigated in this study. Silencing MAP3K3 using siRNA in lung cancer cell lines resulted in decreased cell proliferation, migration and invasion. These effects were associated with down-regulation of the JNK, p38, AKT, and GSK3β pathways as determined using phospho-protein and gene expression array analyses. However, MAP3K3 mRNA and protein overexpression in primary lung tumors correlated significantly with favorable patient survival. Gene cluster and pathway analyses of primary tumor datasets indicated that genes positively-correlated with MAP3K3 are significantly involved in immune response rather than the cell cycle regulators observed using in vitro analyses. These results indicate that although MAP3K3 overexpression has an oncogenic role in vitro, in primary lung adenocarcinomas it correlates with an active immune response in the tumor environment that correlates with improved patient survival. MAP3K3 may potentially not only serve as diagnostic/prognostic markers for patients with lung cancer but also provide an indicator for future investigations into immunomodulatory therapies for lung cancer.

MEKK3 and survivin expression in cervical cancer: association with clinicopathological factors and prognosis

Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3 (MEKK3) is an important protein kinase and a member of the MAPK family, which regulates cellular responses to environmental stress and serves as key integration points along the signal transduction cascade that not only link diverse extracellular stimuli to subsequent signaling molecules but also amplify the initiating signals to ultimately activate effector molecules and induce cell proliferation, differentiation and survival. To explore the relationship between MEKK3 and cell apoptosis, clinicopathology and prognosis, we characterize the expression of MEKK3 and survivin in cervical cancer. MEKK3 and survivin expression was measured by RT-PCR and Western blotting of fresh surgical resections from 30 cases of cervical cancer and 25 cases of chronic cervicitis. Protein expression was detected by tissue microarray and immunochemistry (En Vision) in 107 cases of cervical cancer, 86 cases of cervical intraepithelial neoplasia (CIN), and 35 cases of chronic cervicitis. Expression patterns were analyzed for their association with clinicopathological factors and prognosis in cervical cancer. Expression of MEKK3 and survivin mRNA was significantly higher in cervical cancer than in the controls (p<0.05). MEKK3 and survivin expression differed significantly between cervical carcinoma, CIN, and cervicitis (p<0.05) and correlated with clinical stage, infiltration depth, and lymph node metastasis (p<0.05). MEKK3 expression was positively correlated with survivin (p<0.05). Kaplan-Meier survival analysis showed that MEKK3 and survivin expression, lymph node metastasis, depth of invasion, and FIGO stage reduce cumulative survival. Cox multivariate regression analysis showed that MEKK3, survivin, and clinical staging are independent prognostic factors in cervical cancer (p<0.05). Expression of MEKK3 and survivin are significantly increased in cervical cancer, their overexpression participating in the occurrence and development of cervical cancer, with protein expression and clinical staging acting as independent prognostic factors for patients with cervical cancer.

The expression and role of MEKK3 in renal clear cell carcinoma

To explore the relationship between Mitogen-activated protein kinase/extracellular signal-regulated kinase kinase kinase 3(MEKK3) and cell apoptosis, clinicopathology, and prognosis, we characterize the expression of MEKK3, survivin and stat3 in renal clear cell carcinoma (RCCC). The expressions were measured by RT-PCR and Western blot from 15 cases of RCCC and 15 cases of control group (CG). Protein expression was detected by tissue microarray and immunochemistry in 98 cases of RCCC, 28 cases of CG. Expression patterns were analyzed for their association with pathological factors, correlation and prognosis in RCCC. Expression of MEKK3, survivin and stat3 mRNA was significantly higher in RCCC than in CG (P < 0.01). MEKK3, survivin and stat3 expression differed significantly between pathological grade (P < 0.05) and clinical stage (P < 0.05). MEKK3 expression was positively correlated with survivin and stat3 (P < 0.01). Furthermore, we investigated the role of MEKK3 in RCCC using the technique of RNA silencing via small interfering (siRNA) in ACHN cells. The results indicated that the targeted depletion of MEKK3 caused a dramatic massive apoptotic cell death. Kaplan-Meier survival analysis showed that MEKK3 and survivin expression, pathological grade, and clinical stage reduced cumulative survival. Cox multivariate regression analysis showed that MEKK3, survivin, and clinical staging were independent prognostic factors in renal cancer (P < 0.05). MEKK3 can be used as an important marker of prognostic evaluation in RCCC. The mechanism may be closely related to cell apoptosis. Targeted therapy of MEKK3 may provide a new strategy for treatment of chemotherapeutic-resistant tumors.

AKT/ERK activation is associated with gastric cancer cell resistance to paclitaxel

Paclitaxel (PTX) has shown encouraging activity in the treatment of advanced gastric cancer (GC). However, the fact that more than half of GC patients respond poorly to PTX-based chemotherapies demonstrates the urgent need for biomarkers of PTX sensitivity in GC patients. In the present work, three GC cell lines (BGC-823, HGC-27 and NCI-N87) with different sensitivities to PTX were subjected to DNA microarray analysis. The significantly differentially expressed genes and microRNAs (miRs) were identified and pathway signatures for PTX sensitivity were proposed. Ingenuity Pathway Analysis results showed that the differentially expressed genes were mainly enriched in the ErbB signaling pathway and other pathways. Additionally, the AKT/ERK signaling pathway, which is the pathway downstream of ErbB, was predicted to be active in PTX-resistant GC cell lines. ErbB3 overexpression and AKT/ERK activation in PTX-resistant cell lines were validated, respectively, by quantitative PCR and immunoblotting. Furthermore, 10 miRs were dramatically differently expressed in the three GC cell lines, and a miR-gene network was constructed from these data. Our work uncovered a reliable signature for PTX sensitivity in GC and potential therapeutic targets for GC treatments.

Mitogen activated protein kinase kinase kinase 3 (MAP3K3/MEKK3) overexpression is an early event in esophageal tumorigenesis and is a predictor of poor disease prognosis

BACKGROUND

Mitogen-activated protein kinase kinase kinase3 (MAP3K3/MEKK3) was identified to be differentially expressed in esophageal squamous cell carcinoma (ESCC) using cDNA microarrays by our laboratory. Here in we determined the clinical significance of MEKK3 in ESCC.

METHODS

Immunohistochemical analysis of MEKK3 expression was carried out in archived tissue sections from 93 ESCCs, 47 histologically normal and 61 dysplastic esophageal tissues and correlated with clinicopathological parameters and disease prognosis over up to 7.5 years for ESCC patients.

RESULTS

MEKK3 expression was significantly increased in esophageal dysplasia and ESCC in comparison with normal mucosa (ptrend < 0.001). Kaplan Meier survival analysis showed significantly reduced median disease free survival median DFS = 10 months in patients with MEKK3 positive ESCCs compared to patients with no immunopositivity (median DFS = 19 months, p = 0.04). ESCC patients with MEKK3 positive and lymph node positive tumors had median DFS = 9 months, as compared to median DFS = 21 months in patients who did not show the alterations (p = 0.01). In multivariate Cox regression analysis, combination of MEKK3 overexpression and node positivity [p = 0.015, hazard ratio (HR) = 2.082, 95% CI = 1.154 - 3.756] emerged as important predictor of reduced disease free survival and poor prognosticator for ESCC patients.

CONCLUSIONS

Alterations in MEKK3 expression occur in early stages of development of ESCC and are sustained during disease progression; MEKK3 in combination with lymph node positivity has the potential to serve as adverse prognosticator in ESCC.

Ovarian cancer molecular pathology

Ovarian cancer (OVC) is the fourth leading cause of cancer mortality among women in Europe and the United States. Its early detection is difficult due to the lack of specificity of clinical symptoms. Unfortunately, late diagnosis is a major contributor to the poor survival rates for OVC, which can be attributed to the lack of specific sets of markers. Aside from patients sharing a strong family history of ovarian and breast cancer, including the BRCA1 and BRCA2 tumor suppressor genes mutations, the most used biomarker is the Cancer-antigen 125 (CA-125). CA-125 has a sensitivity of 80 % and a specificity of 97 % in epithelial cancer (stage III or IV). However, its sensitivity is 30 % in stage I cancer, as its increase is linked to several physiological phenomena and benign situations. CA-125 is particularly useful for at-risk population diagnosis and to assess response to treatment. It is clear that alone, CA-125 is inadequate as a biomarker for OVC diagnosis. There is an unmet need to identify additional biomarkers. Novel and more sensitive proteomic strategies such as MALDI mass spectrometry imaging studies are well suited to identify better markers for both diagnosis and prognosis. In the present review, we will focus on such proteomic strategies in regards to OVC signaling pathways, OVC development and escape from the immune response.

Activin and inhibin, estrogens and NFκB, play roles in ovarian tumourigenesis is there crosstalk?

Ovarian cancer may be the most frequently lethal gynaecological malignancy but the heterogeneous nature of the disease and the advanced stage at which it is usually diagnosed, have contributed to the paucity of information relating to its aetiology and pathogenesis. Members of the TGF-β superfamily, estrogen and NFκB have all been implicated in the development and progression of cancers from a wide range of tissues. In the ovary, TGF-β superfamily members and estrogen play key roles in maintaining normal function. To date, little is known about the capacity of NFκB to influence normal ovarian function except that it is ubiquitously expressed. In this review we will highlight the roles that inhibin/activin, estrogen and NFκB, have been attributed within carcinogenesis and examine the potential for crosstalk between these pathways in ovarian cancer pathogenesis.

NF-κB and cancer: a paradigm of Yin-Yang

Recent studies have clearly linked nuclear factor-kappaB (NF-κB), a transcription factor that plays a central role in regulating immune and inflammatory responses, to tumor development, progression, and metastasis as well as tumor therapy resistance. However, it still remains largely unknown on how the tightly regulated NF-κB becomes constitutively activated in tumorigenesis and how the original cancer immunosurveillance function of NF-κB is transformed to be tumorigenic. To address these important issues for cancer prevention and treatment, we discuss current understanding of the molecular mechanisms and molecules involved in the oncogenic activation of NF-κB. We also discuss current understanding of how NF-κB coordinates the inflammatory and malignant cells in tumorigenesis.