Effect of NF-κB inhibitors on the chemotherapy-induced apoptosis of the colon cancer cell line HT-29

Insulin-like growth factor 2 mRNA-binding protein 3 enhanced melanoma migration through regulation of AKT1 and RELA expression

IMP-3 expression is a poor prognostic factor of melanomas and it promotes melanoma cell migration and invasion by a pathway modulating HMGA2 mRNA expression. We tried to identify other putative targets of IMP-3. We identified putative IMP-3-binding RNAs, including AKT1, MAPK3, RB1 and RELA, by RNA immunoprecipitation coupled with next-generation sequencing. IMP-3 overexpression increased AKT and RELA levels in MeWo cells. siRNAs against AKT1 and RELA inhibited MeWo/Full-length IMP-3 cell migration. IMP-3 knockdown of A2058 cells decreased AKT1 and RELA expression and lowered migration ability. Co-transfection of A2058 cells with AKT1- or RELA-expressing plasmids with IMP-3 siRNA restored the inhibitory effects of IMP-3 knockdown on migration. HMGA2 did not influence AKT1 and RELA expression in melanoma cells. Human melanoma samples with high IMP-3 levels also showed high HMGA2, AKT1 and RELA expression. Our results show that IMP-3 enhances melanoma cell migration through the regulation of the AKT1 and RELA axis.

Dermatan Sulfate/Chitosan Nanoparticles Loaded with an Anti-Inflammatory Peptide Increase the Response of Human Colorectal Cancer Cells to 5-Fluorouracil

The gold standard drug for colorectal cancer (CRC) treatment, 5-Fluorouracil (5-FU), induces pharmacological tolerance in long-term management. The transcriptional factor nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) plays a key role in 5-FU resistance. The aim of this work is to study the capability of polyelectrolytes complex nanoparticles of dermatan sulfate (DS) and chitosan (CS), loaded with the anti-inflammatory tripeptide IRW, to sensitize colorectal cancer cells to 5-FU. Fluorescence and flow cytometry studies confirmed the recognition by the nanoformulation, of the cluster of differentiation 44 (CD44) receptor, involved in the initiation and progression of colorectal tumors. Dynamic light scattering (DLS) and flow cytometry reinforced the importance of DS and CD44 receptor in the interaction, as the addition of DS or anti-CD44 antibody blocked the binding. Moreover, the nanoformulation also interacts with 3D colon cancer cultures, namely colonospheres, enriched in cancer stem cells (CSC), subpopulation responsible for drug resistance and metastasis. To evaluate the consequences of this interaction, the subcellular distribution of the transcriptional factor NFκB, is determined by immunofluorescence analysis. Internalization and the intracellular release of IRW inhibited nuclear translocation of NFκB and increased cellular sensitivity to 5-FU. Altogether, the nanoformulation could provide a selective delivery platform for IRW distribution to colorectal tumors, being an innovative strategy toward overcoming 5-FU resistance in CRC therapy.

Chemotherapy-induced phlebitis via the GBP5/NLRP3 inflammasome axis and the therapeutic effect of aescin

BACKGROUND AND PURPOSE

Intravenous infusion of chemotherapy drugs can cause severe chemotherapy-induced phlebitis (CIP) in patients. However, the underlying mechanism of CIP development remains unclear.

EXPERIMENTAL APPROACH

RNA-sequencing analysis was used to identify potential disease targets in CIP. Guanylate binding protein-5 (GBP5) genetic deletion approaches also were used to investigate the role of GBP5 in NLR family pyrin domain containing 3 (NLRP3) inflammasome activation in lipopolysaccharide (LPS) primed murine bone-marrow-derived macrophages (BMDMs) induced by vinorelbine (VIN) in vitro and in mouse models of VIN-induced CIP in vivo. The anti-CIP effect of aescin was evaluated, both in vivo and in vivo.

KEY RESULTS

Here, we show that the expression of GBP5 was upregulated in human peripheral blood mononuclear cells from CIP patients. Genetic ablation of GBP5 in murine macrophages significantly alleviated VIN-induced CIP in the experimental mouse model. Mechanistically, GBP5 contributed to the inflammatory responses through activating NLRP3 inflammasome and driving the production of the inflammatory cytokine IL-1β. Moreover, aescin, a mixture of triterpene saponins extracted from horse chestnut seed, can alleviate CIP by inhibiting the GBP5/NLRP3 axis.

CONCLUSION AND IMPLICATIONS

These findings suggest that GBP5 is an important regulator of NLRP3 inflammasome in CIP mouse model. Our work further reveals that aescin may serve as a promising candidate in the clinical treatment of CIP.

Interplay between Signaling Pathways and Tumor Microenvironment Components: A Paradoxical Role in Colorectal Cancer

The study of the tumor microenvironment (TME) has become an important part of colorectal cancer (CRC) research. Indeed, it is now accepted that the invasive character of a primary CRC is determined not only by the genotype of the tumor cells, but also by their interactions with the extracellular environment, which thereby orchestrates the development of the tumor. In fact, the TME cells are a double-edged sword as they play both pro- and anti-tumor roles. The interaction of the tumor-infiltrating cells (TIC) with the cancer cells induces the polarization of the TIC, exhibiting an antagonist phenotype. This polarization is controlled by a plethora of interconnected pro- and anti-oncogenic signaling pathways. The complexity of this interaction and the dual function of these different actors contribute to the failure of CRC control. Thus, a better understanding of such mechanisms is of great interest and provides new opportunities for the development of personalized and efficient therapies for CRC. In this review, we summarize the signaling pathways linked to CRC and their implication in the development or inhibition of the tumor initiation and progression. In the second part, we enlist the major components of the TME and discuss the complexity of their cells functions.

Synthesis and characterization of polypyridine ruthenium(II) complexes and anticancer efficacy studies in vivo and in vitro

In this article, ligand IPP (IPP = 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-N,N-diphenylaniline) and its three Ru(II) complexes: [Ru(bpy)₂(IPP)](ClO₄)₂ (1) (bpy = 2,2'-bipyridine), [Ru(dmbpy)₂(IPP)](ClO₄)₂ (2) (dmbpy = 4,4'-dimethyl-2,2'-bipyridine), and [Ru(phen)₂(IPP)](ClO₄)₂ (3) (phen = 1,10-phenanthroline) were synthesized and characterized. The anticancer activity in vitro of the complexes was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The scratching and colony-forming experiments confirmed the complexes 1, 2, 3 interfered with the proliferation and migration ability of cells. The accumulation of the complexes in cells was researched and we found that these complexes directly accumulated in mitochondria, then the complexes cause a decline of the mitochondrial membrane potential and induce an increase of intracellular reactive oxygen species (ROS) levels. The growth of B16 cells were inhibited by 1, 2 and 3 at G0/G1 phase. Apoptosis was induced through mitochondrial pathway and the expression of apoptosis-related factors was regulated. In addition, the complexes promoted the transition of poly(ADP-ribose)polymerase (PARP) into the cleaved form (Cleaved PARP), downregulated the anti-apoptotic proteins, and upregulated the pro-apoptotic proteins. Consequently, complexes 1, 2 and 3 exerted their anticancer activity by regulating B-cell lymphoma-2 (Bcl-2) family proteins. Complex 2 showed excellent antitumor effects with a high inhibitory rate of 65.95% in vivo. Taken together, the complexes cause apoptosis in B16 cells through a ROS-mediated mitochondrial dysfunction pathway.

ZhenQi FuZheng formula inhibits the growth of colorectal tumors by modulating intestinal microflora-mediated immune function

Zhenqi Fuzheng formula (ZQFZ), of which the main ingredients are Astragalus membranaceus and Ligustrum lucidum, has immune system regulatory functions and potential anti-tumor bioactivity. The inhibition of colorectal tumor growth by ZQFZ was analyzed in inflammatory cells and B6/JGpt-Apc^em1Cin(MinC)/Gpt (Apc^Min/+) mice. ZQFZ exhibited anti-inflammatory activity by decreasing the phosphorylation of nuclear factor-kappa B (NF-κB) pathway-related proteins in lipopolysaccharide-induced RAW264.7 cells. After 56 days of treatment, ZQFZ alleviated the progression of colorectal cancer (CRC) and increased the body weight and thymic index values of the Apc^Min/+ mice. An analysis of the intestinal microflora showed that ZQFZ affected the abundance of certain immune-related bacteria, which may explain its immunomodulatory effects. Moreover, the percentages of T cells and NK cells in peripheral blood were significantly increased and 15 immune-related cytokines were regulated in serum or the colon or both. ZQFZ upregulated the levels of CD4 and CD8 in the spleen and colorectal tumors and decreased the expression levels of cytotoxic T-lymphocyte-associated protein 4 and programmed death-ligand 1 in colorectal tumors. ZQFZ promoted an anti-tumor immune response and inhibited the occurrence and development of CRC by regulating the immune system. This study provides the experimental basis for the application of ZQFZ as a therapeutic agent for CRC.

SRPK1/AKT axis promotes oxaliplatin-induced anti-apoptosis via NF-κB activation in colon cancer

Background

Colorectal cancer is the third most common diagnosis. Oxaliplatin is used as first-line treatment of colon cancer. However, oxaliplatin resistance greatly reduces its therapeutic effect. SRPK1 involves in pre-mRNA splicing and tumorigenesis. How SRPK1 mediates drug resistance in colon cancer is unknown.

Methods

The expression of SRPK1 was analyzed in the TCGA and the CPTAC pan-cancer samples and detected in colon cancer cell lines and tissues by IHC and western blot. The MTT and TUNEL assay were used to verify the anti-apoptosis ability of colon cancer cell. The activation of NF-κB was determined by luciferase assay and qRT-PCR. AKT, IKK, IκB and their phosphorylation level were verified by western blot.

Results

We found that SRPK1 expression was the second highest in TCGA and the CPTAC pan-cancer samples. The mRNA and protein levels of SRPK1 were increased in tissues from patients with colon cancer. SRPK1 was associated with clinical stage and TNM classifications in 148 cases of colon cancer patients. High SRPK1 levels correlated with poor prognosis (p < 0.001). SRPK1 overexpression enhanced the anti-apoptosis ability of colon cancer cells, whereas SRPK1 silencing had the opposite effect under oxaliplatin treatment. Mechanistically, SRPK1 enhances IKK kinase and IκB phosphorylation to promote NF-κB nuclear translocation to confer oxaliplatin resistance.

Conclusions

Our findings suggest that SRPK1 participates in colon cancer progression and enhances the anti-apoptosis capacity to induce drug resistance in colon cancer cells via NF-κB pathway activation, and thus might be a potential pharmaceutically target for colon cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02954-8.

Itraconazole synergistically increases therapeutic effect of paclitaxel and 99mTc-MIBI accumulation, as a probe of P-gp activity, in HT-29 tumor-bearing nude mice

P-glycoprotein (P-gp), is an important efflux pump involved in chemotherapy resistance in human colon cancer. We investigated the efficacy of itraconazole as a P-gp inhibitor and its therapeutic synergistic relationship to paclitaxel through 99mTc-MIBI accumulation in HT-29 tumor-bearing nude mice. Histopathological screening along with in vitro experiments was done for further assessment. Itraconazole successfully inhibited P-gp mediated 99mTc-MIBI efflux, increasing its in vitro accumulation in itraconazole-receiving dishes. Notably, the co-administration of itraconazole with paclitaxel significantly enhanced the in vitro cytotoxicity effect of paclitaxel in itraconazole + paclitaxel wells containing HT-29 cells. Compared to the control, tumor volume in mice treated with itraconazole, paclitaxel and itraconazole +paclitaxel showed growth suppression approximately by 36.21, 60.02, and 73.3% respectively. And compared to paclitaxel group, the nude mice co-treated with paclitaxel and itraconazole showed suppression of tumor growth by about 33.31 % at the end of the treatment period. Also the biodistribution result showed that the co-administration of itraconazole with paclitaxel raised the mean tumor radioactivity accumulation compared to control and paclitaxel group. When given paclitaxel alone, the ID% of hepatic and cardiac tissue was reduced while co-administration of itraconazole with paclitaxel increased 99mTc-MIBI accumulation in these organs. Furthermore, the histopathological findings confirmed the biodistribution results. These results demonstrate that although monotherapy with itraconazole or paclitaxel has anti-tumor activity against HT-29 human colorectal cancer, a synergistic anti-tumor activity can be achieved when itraconazole is co-administered with paclitaxel. Also, 99mTc-MIBI is an effective radiotracer for monitoring response to treatment in MDR tumors.

Data on the in vitro and in vivo anti-tumor effects of itraconazole, paclitaxel, and the two in combination in HT-29 and YM-1 cancer cell line and HT-29 colon cancer xenograft models

Colon cancer is one of the fatal cancers in the world that metastatic potential and resistance to chemotherapy drugs are outstanding causes of cancer-induced mortality [1], [2], [3], [4]. We have investigated in vitro and in vivo anti-cancer effect of itraconazole and paclitaxel alone and their anti-cancer synergistic effect through MTT assay in YM-1 and HT-29 cell lines and in HT-29 tumor-bearing nude mice. Histopathological experiment was done for further assessment. Also, we evaluated the inhibitory effect of itraconazole on P-gp using specific in vivo biodistribution through ^99mTc-MIBI uptake. ^99mTc-MIBI, a myocardial perfusion imaging agent, is a useful radiotracer in diagnosis of some tumors and the liver and tumor accumulation of ^99mTc-MIBI is changed by P-gp regulators [5], [6], [7], [8]. The data presented in this article are related to the research paper entitled "Itraconazole synergistically increases therapeutic effect of paclitaxel and 99mTc-MIBI accumulation, as a probe of P-gp activity, in HT-29 tumor-bearing nude mice". We hope our preliminary data to be helpful to design the chemotherapy regimen schedule with Itraconazole and Paclitaxel.

Interleukin-1 receptor antagonist enhances chemosensitivity to fluorouracil in treatment of Kras mutant colon cancer

BACKGROUND

Kras mutant colon cancer shows abnormal activation of the nuclear factor kappa-B (NF-κB) pathway, resulting in the proliferation of tumor cells. Treatment with fluorouracil (5-FU) might not achieve the expected inhibition of proliferation of malignant cells based on the fluorouracil-induced activation of the NF-κB pathway.

AIM

To detect whether interleukin (IL)-1 receptor antagonist (IL-1RA) could increase the chemosensitivity to 5-FU by decreasing the activation of the NF-κB pathway and reducing the proliferation of colon cancer cells.

METHODS

Western blot analysis was performed to detect the persistent activation of the NF-κB pathway in colon cancer cell lines. Reverse transcription-polymerase chain reaction was used to detect the IL-1RA-reduced expression levels of IL-6, IL-8, IL-17, IL-21 and TLR4 in colon cancer cell lines. We used a xenograft nude mouse model to demonstrate the downregulation of the NF-κB pathway by blocking the NF-κB-regulated IL-1α feedforward loop, which could increase the efficacy of chemotherapeutic agents in inhibiting tumor cell growth.

RESULTS

IL-1 receptor antagonist could decrease the expression of IL-1α and IL-1β and downregulate the activity of the NF-κB pathway in Kras mutant colon cancer cells. Treatment with 5-FU combined with IL-1RA could increase the chemosensitivity of the SW620 cell line, and decreased expression of the TAK1/NF-κB and MEK pathways resulted in limited proliferation in the SW620 cell line.

CONCLUSION

Adjuvant chemotherapy with IL-1RA and 5-FU has a stronger effect than single chemotherapeutic drugs. IL-1RA combined with fluorouracil could be a potential neoadjuvant chemotherapy in the clinic.

Role of the NF-κB signaling pathway in the pathogenesis of colorectal cancer

The NF-κB signaling pathway is a key regulator of CRC cell proliferation, apoptosis, angiogenesis, inflammation, metastasis, and drug resistance. Over-activation of the NF-κB pathway is a feature of colorectal cancer (CRC). While new combinatorial treatments have improved overall patient outcome; quality of life, cost of care, and patient survival rate have seen little improvement. Suppression of the NF-κB signaling pathway using biological or specific pharmacological inhibitors is a potential therapeutic approach in the treatment of colon cancer. This review summarizes the regulatory role of NF-κB signaling pathway in the pathogenesis of CRC for a better understanding and hence a better management of the disease.

High Expression of PhospholipaseD2 Induced by Hypoxia Promotes Proliferation of Colon Cancer Cells through Activating NF- κ Bp65 Signaling Pathway

Hypoxia is a typical feature of colon cancer occurrence and progression. We have reported that high expression and activity of PhospholipaseD2 (PLD2) induced by hypoxia in colon cancer cells. In order to further investigate the role of PLD2 in colon cancer under hypoxic conditions. MTT assay was used to detect the proliferation of human colon cancer cells (SW480 and SW620) under hypoxic conditions by decrease the PLD2 gene expression or inhibit the activity of PLD2. Expression level of p-P65/T-P65 and Cyclin D1 were detected in those cells treated as above through using western blot and RT-PCR analysis. Effect of NF-Bp65 inhibitor (BAY-117082) on the proliferation and expression level of Cyclin D1 and PLD2 of colon cancer cells under hypoxic conditions were further analysised. As a result, decreased the expression of PLD2 or inhibited the activity of PLD2 leaded to the proliferation of hypoxia colon cancer cells reduced, and along with the expression level of p-P65/T-P65 and Cyclin D1 reduced. However, inhibition the expression level of p-P65/T-P65 lead to the proliferation and expression of Cyclin D1 in those hypoxia colon cancer cells also reduced. In vivo growth decreased in response to PLD2 and NF-Bp65 inhibition. Our study indicates that high expression of PLD2 induced by hypoxia promotes the proliferation of colon cancer cells, and it may elevate the expression level of Cyclin D1 through activating NF-Bp65 signaling pathway. Inhibition of the PLD2 expression may provide a new clue for treatment for colon cancer.

Effects of celastrol on enhancing apoptosis of ovarian cancer cells via the downregulation of microRNA‑21 and the suppression of the PI3K/Akt‑NF‑κB signaling pathway in an in vitro model of ovarian carcinoma

Celastrol has previously been used to treat rheumatoid arthritis, bruises, back pain and additional diseases. At present, efficacy studies predominantly focus on the anti‑inflammatory, antioxidative and antitumor effects of celastrol. However, the effect of celastrol on ovarian cancer cells is not fully elucidated. In the present study, the effects of celastrol were investigated in ovarian cancer cells and the mechanisms involved were explored. In OVCAR3 cells, celastrol was observed to suppress cellular proliferation, induce apoptosis and increase caspase‑9 and ‑3 activity in a dose‑ and time‑dependent manner. The expression levels of microRNA‑21 (miRNA‑21) were reduced, in addition to a reduction in the levels of phosphoinositide 3‑kinase (PI3K)/p‑Akt‑NF (NF)‑κB following treatment with celastrol. Notably, reduced expression of miRNA‑21 replicated the effect of celastrol on OVCAR3 cells and inhibited the PI3K/p‑Akt‑NF‑κB signaling pathway in an in vitro model of ovarian carcinoma. To the best of our knowledge this is the first study to indicate that celastrol may represent a potential agent for the treatment of human ovarian carcinoma, via the induction of apoptosis through the downregulation of miRNA‑21 and the PI3K/Akt‑NF‑κB signaling pathway in an in vitro model of ovarian carcinoma.

Tanshinone IIA enhances chemosensitivity of colon cancer cells by suppressing nuclear factor-κB

The aim of the present study was to investigate the effect and molecular mechanism of tanshinone IIA (TSA) on colon cancer cells. Cell viability was determined using Cell Counting kit-8 assay and the results demonstrated that TSA treatment significantly decreased the cell viability of HCT1116 and COLO205 cells in a dose-dependent manner. TSA treatment also sensitized HCT1116 and COLO205 cells to fluorouracil therapy in a concentration-dependent manner. Western blotting was performed in order to investigate the molecular mechanisms of TSA action and determine the level of phosporylated p65 and nuclear factor-κB (NF-κB)-regulated genes, including vascular endothelial growth factor (VEGF), c-Myc, cyclooxygenase-2 (COX-2) and B-cell lymphoma-2 (Bcl-2). The results revealed that TSA treatment greatly decreased the level of phosphorylated p65 in the nucleus, which indicated the inhibition of NF-κB activation by TSA treatment. TSA also decreased the expression levels of VEGF, c-Myc, COX-2 and Bcl-2. Furthermore, the inhibition of NF-κB activation with the specific inhibitor, pyrrolidine dithiocarbamate, increased the induction of cell death and chemosensitization effect of TSA in colon cancer cells. In conclusion, these results suggest that TSA induces cell death and chemosensitizes colon cancer cells through the suppression of NF-κB signaling.

Pathophysiological mechanisms of death resistance in colorectal carcinoma

Colon cancers develop adaptive mechanisms to survive under extreme conditions and display hallmarks of unlimited proliferation and resistance to cell death. The deregulation of cell death is a key factor that contributes to chemoresistance in tumors. In a physiological context, balance between cell proliferation and death, and protection against cell damage are fundamental processes for maintaining gut epithelial homeostasis. The mechanisms underlying anti-death cytoprotection and tumor resistance often bear common pathways, and although distinguishing them would be a challenge, it would also provide an opportunity to develop advanced anti-cancer therapeutics. This review will outline cell death pathways (i.e., apoptosis, necrosis, and necroptosis), and discuss cytoprotective strategies in normal intestinal epithelium and death resistance mechanisms of colon tumor. In colorectal cancers, the intracellular mechanisms of death resistance include the direct alteration of apoptotic and necroptotic machinery and the upstream events modulating death effectors such as tumor suppressor gene inactivation and pro-survival signaling pathways. The autocrine, paracrine and exogenous factors within a tumor microenvironment can also instigate resistance against apoptotic and necroptotic cell death in colon cancers through changes in receptor signaling or transporter uptake. The roles of cyclooxygenase-2/prostaglandin E2, growth factors, glucose, and bacterial lipopolysaccharides in colorectal cancer will be highlighted. Targeting anti-death pathways in the colon cancer tissue might be a promising approach outside of anti-proliferation and anti-angiogenesis strategies for developing novel drugs to treat refractory tumors.

Icariin-mediated inhibition of NF-κB activity enhances the in vitro and in vivo antitumour effect of 5-fluorouracil in colorectal cancer

Colorectal cancer (CRC) is an aggressive malignancy that has a poor prognosis. 5-Fluorouracil (5-FU) is a first line chemotherapeutic medication used in the treatment of gallbladder cancer; however, the efficacy is below satisfactory. Icariin is a natural compound that is conventionally reported to have activity against a variety of cancers. This study was carried out to investigate the anti-cancer effect of icariin in CRC cells and to determine whether the compound can enhance the antitumour activity of 5-FU. Cell proliferation and apoptosis were measured using an MTT assay and flow cytometry, respectively. The activity of transcription factor NF-κB was determined by EMSA method. The expression of apoptosis- and proliferation-related proteins was determined by western blotting. The in vivo antitumour effect of combination treatment with icariin and 5-FU on CRC was also assessed using a murine model of CRC. Icariin sensitized the CRC cells to 5-FU both in vitro and in vivo. The antitumour activity of icariin and its potentiating effect on the antitumour activity of 5-FU implicated the suppression of NF-κB activity and consequent down-regulation of the gene products regulated by NF-κB. Our results showed that icariin, suppressed tumour growth and enhanced the antitumour activity of 5-FU in CRC by inhibiting NF-κB activity. Therefore, we suggest that combination of icariin with 5-FU might offer a therapeutic benefit to the patients with CRC; however, further studies are required to ascertain this proposition.

MicroRNA-362 induces cell proliferation and apoptosis resistance in gastric cancer by activation of NF-κB signaling

Background

According to cancer-related microRNA (miRNA) expression microarray research available in public databases, miR-362 expression is elevated in gastric cancer. However, the expression and biological role of miR-362 in gastric progression remain unclear.

Methods

miR-362 expression levels in gastric cancer tissues and cell lines were determined using real-time PCR. The roles of miR-362, in promoting gastric cancer cell proliferation and apoptosis resistance, were assessed by different biological assays, such as colony assay, flow cytometry and TUNEL assay. The effect of miR-362 on NF-κB activation was investigated using the luciferase reporter assay, fluorescent immunostaining.

Results

MiR-362 overexpression induced cell proliferation, colony formation, and resistance to cisplatin-induced apoptosis in BGC-823 and SGC-7901 gastric cancer cells. MiR-362 increased NF-κB activity and relative mRNA expression of NF-κB–regulated genes, and induced nuclear translocation of p65. Expression of the tumor suppressor CYLD was inhibited by miR-362 in gastric cancer cells; miR-362 levels were inversely correlated with CYLD expression in gastric cancer tissue. MiR-362 downregulated CYLD expression by binding its 3′ untranslated region. NF-κB activation was mechanistically associated with siRNA-mediated downregulation of CYLD. MiR-362 inhibitor reversed all the effects of miR-362.

Conclusion

The results suggest that miR-362 plays an important role in repressing the tumor suppressor CYLD and present a novel mechanism of miRNA-mediated NF-κB activation in gastric cancer.

Different cellular localization of NF-κB p65 expression as an indicator of different prognoses of stage I-III gastric cancer patients

BACKGROUND

Nuclear factor-κB p65 (NF-κB p65) may play a significant role as a biomarker in tumor progression and metastasis. However, the correlation between cellular localization of NF-κB p65 expression and the prognosis of gastric cancer (GC) patients has not been studied. The present study was designed to investigate the location of NF-κB p65 expression in GC, and evaluate its correlation with clinicopathological parameters of GC patients.

METHODS

NF-κB p65 expressions in GC tissue and corresponding nonmalignant tissue from gastrectomy of 115 stage I-III GC patients were detected by immunohistochemistry. In addition, correlations between the staining results and the clinicopathologic features and survival of the GC patients were analyzed.

RESULTS

The percentage of NF-κB p65 expression in GC tissue and the corresponding nonmalignant tissue was 73.9% and 46.80%, respectively. No significant correlation was found between NF-κB p65 expression and the clinicopathologic parameters. Cox univariate analysis indicated that both nuclear staining and cytoplasmic staining of NF-κB p65 expression correlated with the prognosis of GC patients (log-rank, p = 0.0182; p = 0.0144, respectively).

CONCLUSION

High nuclear expression of NF-κB p65 is an independent prognostic marker predicting a better survival, while high cytoplasmic staining indicates a worse prognosis of GC patients.

NF-κB in colorectal cancer

Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide, responsible for more than half a million deaths annually. CRC is a multistep process that entails the accumulation of genetic/epigenetic aberrations, which lead to the simultaneous failure of protective mechanisms and the activation of tumorigenic pathways. In most cases of CRC a deregulation of the Wnt-signaling pathway is required. The transcription factor nuclear factor κB (NF-κB) has been recognized as a key player in the initiation and propagation of CRC. Under physiological conditions, NF-κB orchestrates the inflammatory process and participates in the modulation of various steps of cell cycle and survival. It is normally kept in an inactive state in the cytoplasm by binding to a group of inhibitory proteins. Upon receipt of a signal, its inhibitor is phosphorylated and proteolytically degraded and NF-κB is actively translocated to the nucleus, where it facilitates target-gene transcription. Recent experimental data reveal the important role of NF-κB in tumor cells as well as in the surrounding "cancerous" and reactive microenvironment. Various tumor cell-derived and contextual cues feed constantly this vicious circuitry sustaining inflammation and promoting proliferation, angiogenesis, invasion and eventually metastasis. Therefore NF-κB along with its upstream and downstream network presents a rational target for therapeutic interventions. Numerous small molecules, inhibitory peptides, antisense RNAs, natural compounds, as well as gene therapy strategies interfere with multiple steps of the NF-κΒ signaling cascade. The design of NF-κΒ-targeted treatment may aid the efforts towards the pursuit of more efficient therapeutic measures devoid of severe systemic side-effects.

γ-Tocotrienol induces paraptosis-like cell death in human colon carcinoma SW620 cells

Colorectal cancer is one of the most serious illnesses among diagnosed cancer. As a new type of anti-cancer composition from tocotrienol-rich fraction of palm oil, γ-tocotrienol is widely used in anti-cancer research. The objectives of this study were to investigate the effects of γ-tocotrienol on human colon cancer SW620 and HCT-8 cells. We showed that treatment with different concentrations of γ-tocotrienol resulted in a dose dependent inhibition of cell growth. Cell death induced by γ-tocotrienol was mediated by a paraptosis-like cell death in SW620 and HCT-8 cells. Real-time RT-PCR and western blot analyses showed that γ-tocotrienol inhibited the expression level of β-catenin, cyclin D1 and c-jun. These data suggest that a paraptosis-like cell death induced by γ-tocotrienol in SW620 cells is associated with the suppression of the Wnt signaling pathway, which offers a novel tool for treating apoptosis-resistance colon cancer.