The Candidate Tumor Suppressor p29ING4 Is Down-Regulated in Human Myeloma Cells and Involved in Their Pro-Angiogenic Properties.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2502-2502
Author(s):  
Nicola Giuliani ◽  
Francesca Morandi ◽  
Simona Colla ◽  
Sara Tagliaferri ◽  
Mirca Lazzaretti ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Molecular Mechanisms ◽  
Plasma Cells ◽  
Statistical Significance ◽  
Myeloma Cell ◽  
Suppressor Gene ◽  
Mrna Levels ◽  
Myeloma Cells ◽  
Candidate Tumor Suppressor ◽  
Nuclear Extracts

Abstract Multiple Myeloma (MM) cells grow into the bone marrow (BM) mainly through the interactions with the microenvironment. The marked induction of angiogenesis by myeloma cells suggests that this process has a pivotal role in the progression of MM. However the molecular mechanisms underlying the regulation of angiogenesis remain unresolved. The new candidate tumor suppressor gene “inhibitor of growth family member 4” (p29ING4) has been recently implicated in solid tumors as a repressor of angiogenesis and tumor growth through the association with p65 subunit of NF-kB and the suppression of angiogenic related gene as IL-8 (Garkavtsev I et al., Nature 2004). In this study first we have evaluated the mRNA expression of p29ING4 in human myeloma cell lines (HMCLs): U266, RPMI-8226, XG-1, XG-6, OPM-2 and JJN3, in EBV+ lines HS-SULTAN and ARH-77 and in purified CD138+ plasmacells (purity >90%) obtained from either 32 MM patients or 6 patients with MGUS by both qualitative RT-PCR and quantitative real time PCR. Healthy CD20+ BM B lymphocytes and/or CD138+ plasmacells obtained from reactive tonsils have been used as controls. p29ING4 has been checked at protein level by western blot on nuclear extracts using a polyclonal anti-p29ING4 Ab. In addition, p29ING4 mRNA levels have been compared with IL-8, VEGF, Ang-1 mRNA levels and correlated with BM angiogenesis in MM patients. The presence of p29ING4 transcript was observed in HMCLs even if p29ING4 mRNA levels were significantly reduced in all HMCLs tested as compared to controls with a median ΔCt p29ING4 (Ct p29ING4-Ct Abl ): 3.2 vs. 0.45 (p<0.05). Consistently a marked down-regulation of p29ING4 protein has been observed in all HMCLs tested compared to controls. The levels of p29ING4 mRNA in HMCLs were independent to the p53 status, whereas, checking the activity of the p50 and p65 subunit of NF-kB by an ELISA-based method, we found that HMCLs with higher p65 activity showed lower levels of p29ING4 mRNA. A significantly negative correlation was observed between p29ING4 and IL-8 mRNA levels (R= −0.84, Spearman 2-tailed test, p=0.04) but not with VEGF (R= −0.07, p=NS) whereas the correlation with ANG-1 did not reach a statistical significance (R=−0.60, p=0.09). Similarly to HMCLs we found that CD138+ MM cells had significantly suppressed levels of p29ING4 mRNA as compared to both normal plasma cells (median ΔCt p29ING4:3.3 vs. 0.47, p=0.03) and MGUS subjects (ΔCt p29ING4:3,3 vs. 0.2 p=0.02) with a mean n-fold expression of 0.11 normalized to controls and 0.09 normalized to MGUS subjects. Consistently lower p29ING4 protein levels were detected in nuclear extracts of CD138+ MM cells as compared to controls. On the other hand we found that IL-8 median levels were significantly higher in BM plasma of MM patients as compared to MGUS subjects (39,3 vs. 25,2 pg/ml p=0.05) and correlated with IL-8 mRNA levels in CD138+ MM cells (R=0.77, p0.041). Interestingly, we observed that MM patients with higher BM IL-8 levels (> 25 pg/ml) have a significantly lower p29ING4 mRNA levels (median ΔCt p29ING4:4.71 vs. 1.9; p=0.04). Finally we found that MM patients with high microvalscular density (MVD) and number of vessels X field have significant lower p29ING4 mRNA levels as compared to those with low MVD (median ΔCt p29ING4:4,8 vs. 2; p=0.04). Our data indicate that the tumor suppressor p29ING4 is down-regulated in myeloma cells and regulate their pro-angiogenic properties.

scholarly journals Chondroitin Synthase 1 Is a Key Molecule in Myeloma Cell-Osteoclast Interactions

2004 ◽  
Vol 280 (16) ◽  
pp. 15666-15672 ◽  
Author(s):  
Larry Yin
Keyword(s):  
Bone Marrow ◽  
Notch Signaling ◽  
Conditioned Medium ◽  
Molecular Mechanisms ◽  
Plasma Cells ◽  
Ex Vivo ◽  
Bone Destruction ◽  
Fold Increase ◽  
Myeloma Cell ◽  
Myeloma Cells

There is a symbiotic relationship between continued growth and proliferation of myeloma cells and the bone destructive process. It has been shown in animal models that blocking bone destruction can result in decreased myeloma tumor burden. Osteoclasts are bone destroying cells found in the bone marrow, and their significance in myeloma is supported by recent findings that osteoclasts alone can support sustained survival and proliferation of purified primary myeloma cells inex vivoco-cultures. However, molecular mechanisms associated with interactions between myeloma cells and osteoclasts remain unclear. Here, we show that when myeloma plasma cells are co-cultured with osteoclasts, chondroitin synthase 1 (CHSY1) is the most significantly altered soluble, secreted protein present in the conditioned medium. RNA interference experiments with CHSY1 small interfering RNA (siRNA) reduced the amount of CHSY1 in the co-culture conditioned medium, and this was associated with a 6.25-fold increase in apoptotic myeloma cells over control co-cultures. CHSY1 contains a Fringe domain, and Fringe is well known for its regulation of Notch signaling via its DDD motif. And interestingly, Fringe domain in CHSY1 has this DDD motif. Shortly after co-culture with osteoclasts, we found that the Notch2 receptor was activated in myeloma cells but Notch1 was not. Activation of Notch2 was down-regulated by CHSY1 siRNA treatment. Modulating Notch signaling by CHSY1 via its DDD motif provides new insight into mechanisms of the interactions between myeloma cells and their bone marrow microenvironment. Targeting this interaction could shed light on treatment of myeloma, which is currently incurable.

Toll-Like Receptor Activation Promotes Multiple Myeloma Cell Growth and Survival By Suppression Of Endoplasmic Reticulum Stress Factor CHOP

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3112-3112 ◽  
Author(s):  
Tina Bagratuni ◽  
Efstathios Kastritis ◽  
Christine Liacos ◽  
Evangelos Eleutherakis-Papaiakovou ◽  
Nikolaos Kanellias ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Mrna Expression ◽  
Cell Lines ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Mrna Levels ◽  
Myeloma Cells ◽  
Growth And Survival ◽  
Pre Treatment

Abstract Multiple Myeloma (MM) patients are vulnerable to infections, which remain a major cause of death, including early death. During infection, human immune cells sense the presence of invading pathogens through the toll-like receptor family (TLR) of receptors. TLRs detect microbes to activate transcriptional programs that orchestrate adaptive responses to specific insults. This means that they induce the endoplasmic reticulum (ER) unfolded protein response (UPR) to accommodate essential protein translation. If the UPR fails to resolve the protein-folding defect, due to severe and prolonged ER stress, apoptosis is activated. However, the timing sequence of the prolonged ER stress has probably implications for ER stress-induced apoptosis that might help cells to adapt under these conditions rather than driving them to apoptosis. Studies have shown that prolonged ER stress occurs in response to microbes and specifically when cells are exposed to lipopolysaccharide (LPS), a TLR4 activator. The prolonged stress, possibly arising from a massive increase in protein synthesis, has shown to suppress CHOP, an apoptosis biomarker, in ER-stressed macrophages, while low levels of CHOP expression promotes B cell survival. Expression and function of TLRs in MM has recently become the focus of several studies and although the regulatory role of TLRs in MM plasma cells has been reported, the underlying molecular mechanisms remain unclear. It has been shown that human myeloma cell lines (HMCL) and primary myeloma cells express high levels of TLRs and specifically of TLR-4 and TLR-9. The aim of our study was to investigate TLR4 signaling in myeloma cells and to explore possible implications with endoplasmic reticulum unfolded protein response as a potential mechanism of drug resistance. We initially investigated whether TLR-4 is expressed in human myeloma cell lines and primary myeloma cells and we found that TLR-4 mRNA is expressed at increased levels (2-10 fold) both in HMCLs and primary cells. To test the hypothesis that TLR-4 signaling may suppress CHOP expression during sustained UPR response, two myeloma cell lines, H929 and U266, were pre-treated with low dose LPS (1 ng/mL) and then subjected to ER stress conditions by treatment with tunicamycin (TM). LPS pre-treatment significantly decreased CHOP mRNA expression after 24 hours. Despite the marked suppression of CHOP, LPS pre-treatment of these myeloma cell lines did not suppress ATF4 mRNA levels which also were not altered by TM treatment. LPS pre-treatment did not also suppress XBP-1 splicing compared to the control ER-stressed cells. To test the specificity of these effects, the same set of experiments where performed on other cancer tissues such as ovarian cancer cell lines. Interestingly, although LPS pre-treatment increased TLR-4 mRNA expression in SKOV3 ovarian cancer cell line, CHOP mRNA levels remained intact prior and after treatment while TM treatment did not make any difference in CHOP mRNA expression. These results suggest the relevance of exploring this pathway in tissues such as plasma cells which are highly dependent on the UPR as a repair mechanism. Pre-treated LPS and TM samples of HMCLs were also subjected to Annexin-PI staining to determine the amount of apoptosis. As expected, pre-treated LPS myeloma cells which were exposed to TM had 30% lower Annexin-FITC stained cells compared to the TM-stressed cells only. These data suggest that blockage of CHOP by TLR4 ligands may promote the growth and survival of MM cells. We then examined the impact of therapy with bortezomib on TLR4 and CHOP mRNA expression in primary tumors cells which were collected before and at day 7 after bortezomib-based therapy from 6 myeloma patients. In 5 out of 6 cases TLR-4 expression was significantly up-regulated and was accompanied with a coupled down-regulation of CHOP mRNA expression. In conclusion, our data suggest that the TLR-4 signaling pathway might provide a translational control pathway which enables cells to carry out essential protein synthesis and avoid CHOP-induced apoptosis. Further exploration of this pathway is needed to establish its role as a potential mechanism of drug resistance. Disclosures: No relevant conflicts of interest to declare.

scholarly journals NDST4 Is a Novel Candidate Tumor Suppressor Gene at Chromosome 4q26 and Its Genetic Loss Predicts Adverse Prognosis in Colorectal Cancer

PLoS ONE ◽  
2013 ◽  
Vol 8 (6) ◽  
pp. e67040 ◽  
Author(s):  
Sheng-Tai Tzeng ◽  
Ming-Hong Tsai ◽  
Chi-Long Chen ◽  
Jing-Xing Lee ◽  
Tzu-Ming Jao ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Suppressor Gene ◽  
Candidate Tumor Suppressor ◽  
Candidate Tumor Suppressor Gene

Identification of the E1A-Regulated Transcription Factor p120E4F as an Interacting Partner of the RASSF1A Candidate Tumor Suppressor Gene

2004 ◽  
Vol 64 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Sarah L. Fenton ◽  
Ashraf Dallol ◽  
Angelo Agathanggelou ◽  
Luke Hesson ◽  
Jalal Ahmed-Choudhury ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Suppressor Gene ◽  
Candidate Tumor Suppressor ◽  
Candidate Tumor Suppressor Gene

Integrative Genomic Analysis Identifies NDRG2 as a Candidate Tumor Suppressor Gene Frequently Inactivated in Clinically Aggressive Meningioma

2005 ◽  
Vol 65 (16) ◽  
pp. 7121-7126 ◽  
Author(s):  
Eriks A. Lusis ◽  
Mark A. Watson ◽  
Michael R. Chicoine ◽  
Meghan Lyman ◽  
Peter Roerig ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Tumor Suppressor Gene ◽  
Genomic Analysis ◽  
Suppressor Gene ◽  
Candidate Tumor Suppressor ◽  
Candidate Tumor Suppressor Gene

scholarly journals Targeting the methyltransferase SETD8 impairs tumor cell survival and overcomes drug resistance independently of p53 status in multiple myeloma

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Laurie Herviou ◽  
Sara Ovejero ◽  
Fanny Izard ◽  
Ouissem Karmous-Gadacha ◽  
Claire Gourzones ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Histone H4 ◽  
Myeloma Cells ◽  
Functional Studies ◽  
Replicative Stress ◽  
Poor Outcome ◽  
Subsequent Decrease ◽  
Lysine Methyltransferase

Abstract Background Multiple myeloma (MM) is a malignancy of plasma cells that largely remains incurable. The search for new therapeutic targets is therefore essential. In addition to a wide panel of genetic mutations, epigenetic alterations also appear as important players in the development of this cancer, thereby offering the possibility to reveal novel approaches and targets for effective therapeutic intervention. Results Here, we show that a higher expression of the lysine methyltransferase SETD8, which is responsible for the mono-methylation of histone H4 at lysine 20, is an adverse prognosis factor associated with a poor outcome in two cohorts of newly diagnosed patients. Primary malignant plasma cells are particularly addicted to the activity of this epigenetic enzyme. Indeed, the inhibition of SETD8 by the chemical compound UNC-0379 and the subsequent decrease in histone H4 methylation at lysine 20 are highly toxic in MM cells compared to normal cells from the bone marrow microenvironment. At the molecular level, RNA sequencing and functional studies revealed that SETD8 inhibition induces a mature non-proliferating plasma cell signature and, as observed in other cancers, triggers an activation of the tumor suppressor p53, which together cause an impairment of myeloma cell proliferation and survival. However, a deadly level of replicative stress was also observed in p53-deficient myeloma cells treated with UNC-0379, indicating that the cytotoxicity associated with SETD8 inhibition is not necessarily dependent on p53 activation. Consistent with this, UNC-0379 triggers a p53-independent nucleolar stress characterized by nucleolin delocalization and reduction of nucleolar RNA synthesis. Finally, we showed that SETD8 inhibition is strongly synergistic with melphalan and may overcome resistance to this alkylating agent widely used in MM treatment. Conclusions Altogether, our data indicate that the up-regulation of the epigenetic enzyme SETD8 is associated with a poor outcome and the deregulation of major signaling pathways in MM. Moreover, we provide evidences that myeloma cells are dependent on SETD8 activity and its pharmacological inhibition synergizes with melphalan, which could be beneficial to improve MM treatment in high-risk patients whatever their status for p53.

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