The insulin-like growth factor system in multiple myeloma: diagnostic and therapeutic potential

Multiple myeloma: signaling pathways and targeted therapy

Multiple myeloma (MM) is the second most common hematological malignancy of plasma cells, characterized by osteolytic bone lesions, anemia, hypercalcemia, renal failure, and the accumulation of malignant plasma cells. The pathogenesis of MM involves the interaction between MM cells and the bone marrow microenvironment through soluble cytokines and cell adhesion molecules, which activate various signaling pathways such as PI3K/AKT/mTOR, RAS/MAPK, JAK/STAT, Wnt/β-catenin, and NF-κB pathways. Aberrant activation of these pathways contributes to the proliferation, survival, migration, and drug resistance of myeloma cells, making them attractive targets for therapeutic intervention. Currently, approved drugs targeting these signaling pathways in MM are limited, with many inhibitors and inducers still in preclinical or clinical research stages. Therapeutic options for MM include non-targeted drugs like alkylating agents, corticosteroids, immunomodulatory drugs, proteasome inhibitors, and histone deacetylase inhibitors. Additionally, targeted drugs such as monoclonal antibodies, chimeric antigen receptor T cells, bispecific T-cell engagers, and bispecific antibodies are being used in MM treatment. Despite significant advancements in MM treatment, the disease remains incurable, emphasizing the need for the development of novel or combined targeted therapies based on emerging theoretical knowledge, technologies, and platforms. In this review, we highlight the key role of signaling pathways in the malignant progression and treatment of MM, exploring advances in targeted therapy and potential treatments to offer further insights for improving MM management and outcomes.

Pathways to therapy resistance: The sheltering effect of the bone marrow microenvironment to multiple myeloma cells

Multiple Myeloma (MM) is a malignant expansion of plasma cells in the bone marrow (BM), resulting in a disease characterized by symptoms of end organ damage from light chain secretion, crowding of the BM, and bone lesions. Although the past two decades have been characterized by numerous novel therapies emerging, the disease remains incurable due to intrinsic or acquired drug resistance. A major player in MM's drug resistance arises from its intimate relationship with the BM microenvironment (BMME). Through stress-inducing conditions, soluble messengers, and physical adhesion to BM elements, the BMME activates numerous pathways in the myeloma cell. This not only propagates myeloma progression through survival and growth signals, but also specific mechanisms to circumvent therapeutic actions. In this review, we provide an overview of the BMME, the role of individual components in MM survival, and various therapy-specific resistance mechanisms reported in the literature.

Correlation Between Bariatric Surgery and the Risk of Multiple Myeloma: Results from an Evidence-Based Strategy

OBJECTIVE

We conducted a meta-analysis of current literature to assess whether bariatric surgery(BS) has a positive effect on reducing the risk of multiple myeloma(MM).

METHODS

Relevant studies meeting the criteria were systematically reviewed using databases such as PubMed, Web of Science, Embase (Ovid platform), MEDLINE, and the Cochrane Library. The meta-analysis utilized hazard ratios (RR) and 95% confidence intervals (CI) to analyze the correlation between BS and the risk of MM. STATA software (version 12.0) was employed for the meta analysis.

RESULTS

The meta-analysis included 10 eligible studies, involving 2,452,503 patients with obesity. The results demonstrated a significant reduction in the risk of multiple myeloma in patients with obesity after bariatric surgery compared to non-surgical patients with obesity (RR = 0.51, 95%CI: 0.31-0.84). Subgroup analyses revealed a decreased probability of developing multiple myeloma in European patients with obesity and North American patients with obesity who underwent bariatric surgery. Studies with a sample size greater than or equal to 100,000 indicated a significantly reduced risk of multiple myeloma in patients with obesity undergoing bariatric surgery compared to the non-surgical group (RR: 0.45, 95%CI: 0.23-0.88, P < 0.02). Two publications before 2010 showed no significant difference in the incidence of multiple myeloma between the surgical and non-surgical groups (RR: 0.61, 95% CI: 0.14-2.63, P = 0.504), while publications after 2010 demonstrated a reduced incidence in the surgical group (RR: 0.51, 95% CI: 0.30-0.86, P = 0.012).

CONCLUSION

Our meta-analysis results suggest a reduced risk of multiple myeloma in patients with obesity following bariatric surgery.

PROSPERO REGISTRATION

CRD42023485668.

NT157 exhibits antineoplastic effects by targeting IRS and STAT3/5 signaling in multiple myeloma

Multiple myeloma (MM) is a prevalent hematological malignancy with high recurrence and no definitive cure. The current study revisits the role of the IGF1/IGF1R axis in MM, introducing a novel inhibitor, NT157. The IGF1/IGF1R pathway is pivotal in MM, influencing cell survival, proliferation, and migration and impacting patient survival outcomes. NT157 targets intracellular proteins such as IRS and STAT proteins and demonstrates antineoplastic potential in hematological malignancies and solid tumors. In the present study, we assessed IGF1R signaling-related gene expression in MM patients and healthy donors, unveiling significant distinctions. MM cell lines displayed varying expression patterns of IGF1R-related proteins. A gene dependence analysis indicated the importance of targeting receptor and intracellular elements over autocrine IGF1. NT157 exhibited inhibitory effects on MM cell viability, clonal growth, cell cycle progression, and survival. Moreover, NT157 reduced IRS2 expression and STAT3, STAT5, and RPS6 activation and modulated oncogenes and tumor suppressors, fostering a tumor-suppressive molecular profile. In summary, our study demonstrates that the IGF1/IGF1R/IRS signaling axis is differentially activated in MM cells and the NT157's capacity to modulate crucial molecular targets, promoting antiproliferative effects and apoptosis in MM cells. NT157 may offer a multifaceted approach to enhance MM therapy.

Body size and risk of multiple myeloma in the Black Women's Health Study

BACKGROUND

Obesity is an established risk factor for multiple myeloma (MM). Relatively few prior studies, however, have evaluated associations in Black populations.

METHODS

Among 55,276 participants in the Black Women's Health Study, a prospective U.S. cohort established in 1995, we confirmed 292 incident diagnoses of MM over 26 years of follow-up. Multivariable Cox proportional hazard models, adjusted for age and putative MM risk factors, were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of usual body mass index (BMI), BMI at age 18, height, and waist-to-hip ratio with MM.

RESULTS

Compared to women with a usual adult BMI < 25 kg/m2, the HR associated with a usual adult BMI ≥ 35 kg/m2 was 1.38 (95% CI: 0.96, 1.98). For early adult BMI, the HR comparing women with BMI ≥ 25 vs. <25 kg/m2 was 1.57 (95% CI: 1.08, 2.28). Women who were heavy in both early and later life had the highest risk compared to those who were lean at both time points (HR: 1.60; 95% CI: 1.02, 2.52). Height was also associated with the risk of MM; the HR per 10 cm was 1.21 (95% CI: 1.02, 1.43).

CONCLUSIONS

These results indicate that high early adult BMI is associated with a 57% increased risk of MM in Black women and potentially highlight the importance of weight control as a preventive measure.

Conceptualizing an Integrative Multiple Myeloma Care: The Role of Nutrition, Supplements, and Complementary Modalities

Multiple Myeloma (MM) is the second most prevalent hematologic malignancy, and its incidence has been increasing enormously in recent years. The prognosis of MM has changed radically with the introduction of new drugs that have improved life expectancy; recurrences are a common occurrence during the course of the disease and are characterized by an increase in refractory to treatment. Moreover, MM patients are challenged by quality of life-related concerns while limited conventional therapy may be offered. This includes bone pain and dialysis due to the complications of acute renal failure. We, therefore, believe that it is very important to add new treatment modalities, including supplements, nutritional modifications, acupuncture, and mind-body therapies, with the goal of improving treatment tolerance, effectiveness, and patients' quality of life. Moreover, many patients use some of these supplements on their own, in the hope of reducing the side effects, so it is even more important to know their action and potential. The purpose of this review is to illustrate all these strategies potentially available to enrich our approach to this, to date, incurable disease.

Novel_circ_003686 regulates the osteogenic differentiation of MSCs in patients with myeloma bone disease through miR-142-5p/IGF1 axis

Objectives

Circ_003686 is a novel_circRNA with abnormally low expression found in the samples of multiple myeloma bone disease (MBD) patients. The current research intended to investigate the effects of novel_circ_003686 in osteogenesis-induced differentiation of bone marrow mesenchymal stem cells (BMSCs) in MBD.

Methods

BMSCs were extracted from MBD patients and normal participants, the pcDNA3.1 encoding the circ_003686 (ov-circ_003686), miR-142-5p-mimic/inhibitor and siRNA oligonucleotides targeting insulin like growth factor 1 (IGF1, si-IGF1) were applied to intervene circ_003686, miR-142-5p and IGF1 levels, respectively. Results: Results showed that ov-circ_003686 could mediate the osteogenesis-induced differentiation of MBD-BMSC, and luciferase assay and RIP experiments confirmed that circ_003686 could bind to miR-142-5p. MiR-142-5p-inhibitor helped osteogenesis-induced differentiation, while miR-142-5p-mimic inhibited osteogenesis-induced differentiation and reversed the promoting effect of ov-circ_003686, suggesting that circ_003686/miR-142-5p axis participated in osteogenesis-induced differentiation of MBD-BMSC. In addition, miR-142-5p binds to the target gene IGF1 and negatively adjust its expression. Si-IGF1 significantly inhibited the osteogenesis-induced differentiation and reversed the promotion effects of miR-142-5p-inhibitor and ov-circ_003686. Moreover, circ_003686/miR-142-5p/IGF1 axis meaningfully regulates protein expressions in the PI3K/AKT pathway.

Conclusion

In conclusion, this research confirmed that circ_003686 regulated the osteogenesis-induced differentiation of MBD-BMSC by sponging miR-142-5p and mediating IGF1, and the PI3K/AKT pathway may also be involved.

Obesity and multiple myeloma: emerging mechanisms and perspectives

Obesity is a global pandemic that has been associated with the development of breast, endometrial, large intestine, renal, esophageal, and pancreatic cancer. Obesity is also involved in the development of cardiovascular disease and type 2 diabetes mellitus. Recently, an increase in the incidence of obesity-related cancers has been reported. Multiple myeloma (MM) is the second most common hematological malignancy, after lymphoma. The aim of this review is to examine the epidemiological data on obesity and MM, assess the effect of obesity on MM outcomes, evaluate the possible mechanisms through which obesity might increase the incidence of MM and provide the effects of obesity management on MM. Current evidence indicates that obesity may have an impact on the progression of monoclonal gammopathy of undetermined significance (MGUS) to MM and increase the prevalence of MM. However, data regarding the effect of obesity on MGUS incidence are controversial; further studies are needed to examine whether obesity affects the development of MGUS or the progression of MGUS to MM. In addition, obesity affects MM outcomes. Increased BMI is associated with decreased survival in patients with MM, while data regarding the effect of obesity on newly diagnosed MM subjects and autologous stem cell transplantation are limited. Interestingly, the obesity paradox may also apply to patients with relapsed/refractory MM who are overweight or obese, because they may have a survival advantage. The pathophysiological pathways linking obesity to MM are very complicated and include bone marrow adipose tissue; adipokines, such as adiponectin, leptin, resistin, and visfatin; inflammatory cytokines and growth factors, such as TNF-α and IL-6; hormones including insulin and the insulin-like growth factor system as well as sex hormones. In terms of the effect of pharmacological management of obesity, orlistat has been shown to alter the proliferation of MM cells, whereas no data exist on glucagon-like peptide-1 receptor agonists, naltrexone/bupropion, or phentermine/topiramate. Bariatric surgery may be associated with a reduction in the incidence of MM, however, further studies are needed.

Anti-Angiogenic Activity of Drugs in Multiple Myeloma

Angiogenesis represents a pivotal hallmark of multiple myeloma (MM) that correlates to patients’ prognosis, overall survival, and drug resistance. Hence, several anti-angiogenic drugs that directly target angiogenic cytokines (i.e., monoclonal antibodies, recombinant molecules) or their cognate receptors (i.e., tyrosine kinase inhibitors) have been developed. Additionally, many standard antimyeloma drugs currently used in clinical practice (i.e., immunomodulatory drugs, bisphosphonates, proteasome inhibitors, alkylating agents, glucocorticoids) show anti-angiogenic effects further supporting the importance of inhibiting angiogenesis from potentiating the antimyeloma activity. Here, we review the most important anti-angiogenic therapies used for the management of MM patients with a particular focus on their pharmacological profile and on their anti-angiogenic effect in vitro and in vivo. Despite the promising perspective, the direct targeting of angiogenic cytokines/receptors did not show a great efficacy in MM patients, suggesting the need to a deeper knowledge of the BM angiogenic niche for the design of novel multi-targeting anti-angiogenic therapies.

Contribution of the Tumor Microenvironment to Metabolic Changes Triggering Resistance of Multiple Myeloma to Proteasome Inhibitors

Virtually all patients with multiple myeloma become unresponsive to treatment with proteasome inhibitors over time. Relapsed/refractory multiple myeloma is accompanied by the clonal evolution of myeloma cells with heterogeneous genomic aberrations, diverse proteomic and metabolic alterations, and profound changes of the bone marrow microenvironment. However, the molecular mechanisms that drive resistance to proteasome inhibitors within the context of the bone marrow microenvironment remain elusive. In this review article, we summarize the latest knowledge about the complex interaction of malignant plasma cells with its surrounding microenvironment. We discuss the pivotal role of metabolic reprograming of malignant plasma cells within the tumor microenvironment with a subsequent focus on metabolic rewiring in plasma cells upon treatment with proteasome inhibitors, driving multiple ways of adaptation to the treatment. At the same time, mutual interaction of plasma cells with the surrounding tumor microenvironment drives multiple metabolic alterations in the bone marrow. This provides a tumor-promoting environment, but at the same time may offer novel therapeutic options for the treatment of relapsed/refractory myeloma patients.

Evaluation of Serum Levels of Insulin-Like Growth Factor 1 and Insulin-Like Growth Factor-Binding Protein 3 in Patients With Colorectal Cancer: A Case-Control Study

Background/aim: Limited information is available about the relationship between colorectal cancer (CRC) and serum concentration of insulin-like growth factor 1 (IGF1) and insulin-like growth factor-binding protein 3 (IGFBP3). This study aims to compare the serum levels of IGF1and IGFBP3 in colorectal cancer cases and controls and to assess the relationship between their level and the demographic and histopathological characteristics.

Methods: A case-control study in which 50 patients with colorectal cancer and 50 controls matched by gender and age were compared regarding the demographic characteristics and the level of both IGF1 and IGFBP3. The correlation with different clinicopathological features was assessed.

Results: Levels of IGF1 were significantly higher while levels of IGFBP3 were significantly lower among cases compared to control. IGF1 was significantly higher among patients with liver metastasis, lymph node (LN) spread, and lymphovenous invasions and did not show significant association with gender, smoking status, family history, or primary site of colorectal cancer. Lower IGFBP3 was significantly high among patients with liver and lymph node metastasis, lymphovenous invasion, and patients with positive family history. This significant negative correlation was also detected between IGFBP3 levels and the size of the tumor.

Conclusions: High IGF1 levels and low concentrations of IGFBP3 are related to colorectal cancer and were significantly associated with liver metastasis, lymph node spread, and lymphovenous invasions. Further research is recommended to investigate if circulating IGF1 and IGFBP3 levels can be used to identify people at high risk of colorectal cancer and to investigate potential lifestyle or pharmaceutical ways to lower IGF1 bioactivity as a risk reduction strategy.

Identification of Candidate Biomarkers and Prognostic Analysis in Colorectal Cancer Liver Metastases

Background

Colorectal cancer (CRC), one of the most common malignant tumors worldwide, has a high mortality rate, especially for patients with CRC liver metastasis (CLM). However, CLM pathogenesis remains unclear.

Methods

We integrated multiple cohort datasets and databases to clarify and verify potential key candidate biomarkers and signal transduction pathways in CLM. GEO2R, DAVID 6.8, ImageGP, STRING, UALCAN, ONCOMINE, THE HUMAN PROTEIN ATLAS, GEPIA 2.0, cBioPortal, TIMER 2.0, DRUGSURV, CRN, GSEA 4.0.3, FUNRICH 3.1.3 and R 4.0.3 were utilized in this study.

Results

Sixty-three pairs of matched colorectal primary cancer and liver metastatic gene expression profiles were screened from three gene expression profiles (GSE6988, GSE14297 and GSE81558). Thirty-one up-regulated genes and four down-regulated genes were identified from these three gene expression profiles and verified by another gene expression profiles (GSE 49355) and TCGA database. Two pathways (IGFBP-IGF signaling pathway and complement-coagulation cascade), eighteen key differentially expressed genes (DEGs), six hub genes (SPARCL1, CDH2, CP, HP, TF and SERPINA5) and two biomarkers (CDH2 and SPARCL1) with significantly prognostic values were screened by multi-omics data analysis and verified by Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) cohort.

Conclusions

In this study, we identified a robust set of potential candidate biomarkers in CLM, which would provide potential value for early diagnosis and prognosis, and would promote molecular targeting therapy for CRC and CLM.

Diabetes, but not pre-diabetes, is associated with shorter time to second-line therapy and worse outcomes in patients with multiple myeloma

About 20% of MM patients have T2DM. We assessed the impact of T2DM/pre-T2DM on MM progression and OS. We collected retrospective data of newly diagnosed MM patients in Maccabi health services, Israel, between 2012 and 2016. The study included 503 MM patients, median age 67.2 years (IQR: 33.5-91.2). Median follow-up was 32 months (IQR 19.4-47). T2DM and pre-T2DM were recorded in 24.1% and 51% patients, respectively. Median TT2T and OS in the cohort were 17.5 months (95% confidence interval (CI) 15-20) and unreached, respectively. T2DM patients had shorter TT2T (HR = 1.31, 95%CI 1.0-1.72, p=.047), particularly transplanted patients; 20.2 vs. 40 months (HR = 2.09, 95%CI 1.18-3.71, p=.012). In a multivariable model, T2DM had a borderline significant risk of all-cause mortality, adjusted HR 1.38 (p=.09). Pre-diabetes had no impact on TT2T or OS. T2DM predicted a shorter TT2T, particularly in transplanted patients, and tended to be associated with shorter survival.

Obesity as a Possible Risk Factor for Progression from Monoclonal Gammopathy of Undetermined Significance Progression into Multiple Myeloma: Could Myeloma Be Prevented with Metformin Treatment?

Obesity is increasingly associated with the transformation of monoclonal gammopathy of undetermined significance (MGUS) into multiple myeloma (MM). Obesity, MGUS, and MM share common etiopathogenesis mechanisms including altered insulin axis and the action of inflammatory cytokines. Consistent with this interconnection, metformin could predominantly exert inhibition of these pathophysiological factors and thus be an attractive therapeutic option for MGUS. Despite the possible clinical significance, only a limited number of epidemiological studies have focused on obesity as a risk factor for MGUS and MM. This review describes multiple biological pathways modulated by metformin at the cellular level and their possible impacts on the biology of MGUS and its progression into MM.

Possible mechanisms of action of clarithromycin and its clinical application as a repurposing drug for treating multiple myeloma

Clarithromycin (CAM), a semisynthetic macrolide antibiotic, is a widely used antibacterial drug. Recently, the efficacy of CAM as an add-on drug for treating multiple myeloma (MM) has been noted. Its effect on treating MM has been confirmed in combination chemotherapies that include CAM. However, a single treatment of CAM has no efficacy for treating MM. Many myeloma growth factors (MGFs) including interleukin (IL)-6 are known to be closely involved in the development of MM. CAM has been shown to suppress many MGFs, particularly IL-6. The possible mechanisms of action of CAM in treating MM have been suggested to include its immunomodulatory effect, autophagy inhibition, reversibility of drug resistance, steroid-sparing/enhancing effect and suppression of MGFs. In addition, MM is characterised by uncontrolled cell growth of monoclonal immunoglobulin (Ig)-producing neoplastic plasma cells. Large quantities of unfolded or misfolded Ig production may trigger considerable endoplasmic reticulum stress. Thus, MM is originally a fragile neoplasm particularly susceptible to autophagy-, proteasome- and histone deacetylase 6-inhibitors. Taken together, CAM plays an important role in MM treatments through its synergistic mechanisms. In addition, CAM with its pleiotropic effects on cytokines including IL-6 and indirect antiviral effects might be worth a try for treating COVID-19.

Components of metabolic syndrome in patients with multiple myeloma and smoldering multiple myeloma

BACKGROUND

The prevalences of diabetes mellitus and hypertension, both of which are components of metabolic syndrome, are known to be increased among patients with multiple myeloma (MM), but remain undetermined among patients with smoldering MM (SMM).

METHODS

Changes in various components of metabolic syndrome were investigated during the follow-up of patients with either MM or SMM compared to healthy controls. The data of 153 patients (105 with MM and 48 with SMM) and 138 controls were accessed from our medical center's records between 2008 and 2015. We analyzed the patients' data at diagnosis (baseline) and after 1, 3, and 5 years of follow-up.

RESULTS

Patients with SMM had a significantly higher prevalence of diabetes, hypertension, and dyslipidemia at baseline compared to controls. A multivariate Cox regression analysis revealed a higher risk to develop dyslipidemia after 1, 3, and 5 years of follow-up among the SMM patients. The MM patients had a higher risk to develop diabetes after 1 year, hypertension after 5 years, and dyslipidemia after 1, 3, and 5 years of follow-up.

CONCLUSIONS

These data demonstrate that patients with SMM and those with MM are more prone to develop various components of metabolic syndrome, and they stress the importance of following-up metabolic syndrome components in both groups of patients.

Lipid rafts as signaling hubs in cancer cell survival/death and invasion: implications in tumor progression and therapy: Thematic Review Series: Biology of Lipid Rafts

Cholesterol/sphingolipid-rich membrane domains, known as lipid rafts or membrane rafts, play a critical role in the compartmentalization of signaling pathways. Physical segregation of proteins in lipid rafts may modulate the accessibility of proteins to regulatory or effector molecules. Thus, lipid rafts serve as sorting platforms and hubs for signal transduction proteins. Cancer cells contain higher levels of intracellular cholesterol and lipid rafts than their normal non-tumorigenic counterparts. Many signal transduction processes involved in cancer development (insulin-like growth factor system and phosphatidylinositol 3-kinase-AKT) and metastasis [cluster of differentiation (CD)44] are dependent on or modulated by lipid rafts. Additional proteins playing an important role in several malignant cancers (e.g., transmembrane glycoprotein mucin 1) are also being detected in association with lipid rafts, suggesting a major role of lipid rafts in tumor progression. Conversely, lipid rafts also serve as scaffolds for the recruitment and clustering of Fas/CD95 death receptors and downstream signaling molecules leading to cell death-promoting raft platforms. The partition of death receptors and downstream signaling molecules in aggregated lipid rafts has led to the formation of the so-called cluster of apoptotic signaling molecule-enriched rafts, or CASMER, which leads to apoptosis amplification and can be pharmacologically modulated. These death-promoting rafts can be viewed as a linchpin from which apoptotic signals are launched. In this review, we discuss the involvement of lipid rafts in major signaling processes in cancer cells, including cell survival, cell death, and metastasis, and we consider the potential of lipid raft modulation as a promising target in cancer therapy.

MiR-148a inhibits oral squamous cell carcinoma progression through ERK/MAPK pathway via targeting IGF-IR

OBJECTIVE

The current study aimed to investigate the functional roles and clinical significance of microRNA-148a (miR-148a) in the progression of oral squamous cell carcinoma (OSCC).

METHODS

Relative expression of miR-148a in OSCC cells and tissues were detected using quantitative real-time polymerase chain reaction (qRT-PCR). Chi-square test was performed to estimate the relationship between miR-148a expression and clinical characteristics of OSCC patients. Cell transfection was carried out using Lipofectamine® 2000. Biological behaviors of tumor cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and transwell assays. Bioinformatics analysis and luciferase reporter assay were used to identify the target genes of miR-148a. Protein expression was detected through Western blot analysis.

RESULTS

MiR-148a expression was obviously decreased in OSCC tissues and cells, and such down-regulation was closely correlated with lymph node metastasis (P=0.027) and tumor node metastasis (TNM) stage (P=0.001) of OSCC patients. miR-148a overexpression could significantly impair OSCC cell proliferation, migration and invasion in vitro (P<0.05 for all). Insulin-like growth factor-I receptor (IGF-IR) was a potential target of miR-148a. MiR-148a could inhibit ERK/MAPK signaling pathway through targeting IGF-IR.

CONCLUSION

MiR-148a plays an anti-tumor role in OSCC and inhibits OSCC progression through suppressing ERK/MAPK pathway via targeting IGF-IR.

Novel conjugates of endoperoxide and 4-anilinoquinazoline induce myeloma cell apoptosis by inhibiting the IGF1-R/AKT/mTOR signaling pathway

4-anilinoquinazoline-containing inhibitors of the epidermal growth factor receptor (EGFR) are widely used in non-small cell lung cancer patients with mutated EGFR, but they are less effective in multiple myeloma (MM), a fatal malignancy derived from plasma cells. The present study designed a series of novel compounds by conjugating a peroxide bridge to the 4-anilinoquinazoline pharmacophore. Further studies showed that these agents such as 4061 and 4065B displayed potent activity to induce MM cell apoptosis by upregulating pro-apoptotic p53 and Bax while downregulating pro-survival Bcl-2. The mechanistic analysis revealed that both 4061 and 4065B inhibited IGF1-R, AKT and mTOR activation in a concentration dependent manner but had no effects on the expression of their total proteins, suggesting the conjugates of endoperoxide and 4-anilinoquinazoline may exert its anti-myeloma activity by targeting the IGF1-R/AKT/mTOR pathway.

Increased expression of insulin-like growth factor-1 receptor predicts poor prognosis in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a lethal disease worldwide. In this study, we sought to explore the expression of insulin-like growth factor-1 receptor (IGF-1R) and its prognostic value in HCC.The expressions of IGF-1R mRNA and protein were estimated using quantitative real-time polymerase chain reaction and immunohistochemistry assays, respectively. The association between IGF-1R expression and clinicopathologic characteristic of patients with HCC was analyzed through Chi-squared test. Kaplan-Meier analysis and multivariate Cox analysis were performed to analyze prognostic value of IGF-1R in HCC.The IGF-1R was significantly upregulated in HCC tissues at both mRNA and protein levels compared with adjacent normal ones (P < .01). Its expression was associated with tumor node metastasis stage (P = .037) and lymph node metastasis (P = .027) of patients with HCC. Patients with HCC with high expression of IGF-1R had worse overall survival than those with low expression. IGF-1R might be a potential prognostic biomarker for HCC (hazard ratio [HR] = 1.912, 95% confidence interval [CI]: 1.023-3.572, P = .042).The IGF-1R expression level is upregulated in HCC tissues and may act as a prognostic biomarker for the disease.

Insulin-Like Growth Factor 2 (IGF2) Signaling in Colorectal Cancer-From Basic Research to Potential Clinical Applications

Colorectal cancer (CRC) is one of the most common cancers in men and women worldwide as well as is the leading cause of death in the western world. Almost a third of the patients has or will develop liver metastases. While genetic as well as epigenetic mechanisms are important in CRC pathogenesis, the basis of the most cases of cancer is unknown. High spatial and inter-patient variability of the molecular alterations qualifies this cancer in the group of highly heterogeneous tumors, which makes it harder to elucidate the mechanisms underlying CRC progression. Determination of highly sensitive and specific early diagnosis markers and understanding the cellular and molecular mechanism(s) of cancer progression are still a challenge of the current era in oncology of solid tumors. One of the accepted risk factors for CRC development is overexpression of insulin-like growth factor 2 (IGF2), a 7.5-kDa peptide produced by liver and many other tissues. IGF2 is the first gene discovered to be parentally imprinted. Loss of imprinting (LOI) or aberrant imprinting of IGF2 could lead to IGF2 overexpression, increased cell proliferation, and CRC development. IGF2 as a mitogen is associated with increased risk of developing colorectal neoplasia. Higher serum IGF2 concentration as well as its tissue overexpression in CRC compared to control are associated with metastasis. IGF2 protein was one of the three candidates for a selective marker of CRC progression and staging. Recent research indicates dysregulation of different micro- and long non-coding RNAs (miRNAs and lncRNAs, respectively) embedded within the IGF2 gene in CRC carcinogenesis, with some of them indicated as potential diagnostic and prognostic CRC biomarkers. This review systematises the knowledge on the role of genetic and epigenetic instabilities of IGF2 gene, free (active form of IGF2) and IGF-binding protein (IGFBP) bound (inactive form), paracrine/autocrine secretion of IGF2, as well as mechanisms of inducing dysplasia in vitro and tumorigenicity in vivo. We have tried to answer which molecular changes of the IGF2 gene and its regulatory mechanisms have the most significance in initiation, progression (including liver metastasis), prognosis, and potential anti-IGF2 therapy in CRC patients.

Investigational Monoclonal Antibodies in the Treatment of Multiple Myeloma: A Systematic Review of Agents under Clinical Development

BACKGROUND

Immunotherapy for multiple myeloma (MM) has been the focus in recent years due to its myeloma-specific immune responses. We reviewed the literature on non-Food and Drug Administration (FDA) approved monoclonal antibodies (mAbs) to highlight future perspectives. We searched PubMed, EMBASE, Web of Science, Cochrane Library and ClinicalTrials.gov to include phase I/II clinical trials. Data from 39 studies (1906 patients) were included. Of all the agents, Isatuximab (Isa, anti-CD38) and F50067 (anti-CXCR4) were the only mAbs to produce encouraging results as monotherapy with overall response rates (ORRs) of 66.7% and 32% respectively. Isa showed activity when used in combination with lenalidomide (Len) and dexamethasone (Dex), producing a clinical benefit rate (CBR) of 83%. Additionally, Isa used in combination with pomalidomide (Pom) and Dex resulted in a CBR of 73%. Indatuximab Ravtansine (anti-CD138 antibody-drug conjugate) produced an ORR of 78% and 79% when used in combination with Len-Dex and Pom-Dex, respectively.

CONCLUSIONS

Combination therapy using mAbs such as indatuximab, pembrolizumab, lorvotuzumab, siltuximab or dacetuzumab with chemotherapy agents produced better outcomes as compared to monotherapies. Further clinical trials investigating mAbs targeting CD38 used in combination therapy are warranted.

Emerging immune targets for the treatment of multiple myeloma

We reviewed emerging immune strategies for multiple myeloma (MM) therapy excluding US FDA approved drugs. In relapsed refractory MM, isatuximab (anti-CD38) monotherapy achieved overall response (OR) of 24%. Other monoclonal antibodies that have shown efficacy in combination therapy include siltuximab (OR: 66%), indatuximab (OR: 78%), isatuximab (OR: 64.5%), pembrolizumab (OR: 60%), bevacizumab (OR: 70%), dacetuzumab (OR: 39%) and lorvotuzumab (OR: 56.4%). No OR was observed with monotherapy using BI-505, siltuximab, bevacizumab, AVE-1642, figitumumab, atacicept, milatuzumab, dacetuzumab, lucatumumab, IPH2101, lorvotuzumab, BT062 and nivolumab. We included seven clinical trials on chimeric antigen receptor (CAR) T cells. CAR T-cell targets include BCMA, CD19, KLC and CD138. A recent experience of CAR T-cell (B-cell maturation antigen) therapy in advanced MM has shown global response of 100%. The future of monoclonal antibodies and adoptive T cells for MM treatment seems promising.

The Epigenome in Multiple Myeloma: Impact on Tumor Cell Plasticity and Drug Response

Multiple myeloma (MM) is a clonal plasma cell malignancy that develops primarily in the bone marrow (BM), where reciprocal interactions with the BM niche foster MM cell survival, growth, and drug resistance. MM cells furthermore reshape the BM to their own needs by affecting the different BM stromal cell types resulting in angiogenesis, bone destruction, and immune suppression. Despite recent advances in treatment modalities, MM remains most often incurable due to the development of drug resistance to all standard of care agents. This underscores the unmet need for these heavily treated relapsed/refractory patients. Disruptions in epigenetic regulation are a well-known hallmark of cancer cells, contributing to both cancer onset and progression. In MM, sequencing and gene expression profiling studies have also identified numerous epigenetic defects, including locus-specific DNA hypermethylation of cancer-related and B cell specific genes, genome-wide DNA hypomethylation and genetic defects, copy number variations and/or abnormal expression patterns of various chromatin modifying enzymes. Importantly, these so-called epimutations contribute to genomic instability, disease progression, and a worse outcome. Moreover, the frequency of mutations observed in genes encoding for histone methyltransferases and DNA methylation modifiers increases following treatment, indicating a role in the emergence of drug resistance. In support of this, accumulating evidence also suggest a role for the epigenetic machinery in MM cell plasticity, driving the differentiation of the malignant cells to a less mature and drug resistant state. This review discusses the current state of knowledge on the role of epigenetics in MM, with a focus on deregulated histone methylation modifiers and the impact on MM cell plasticity and drug resistance. We also provide insight into the potential of epigenetic modulating agents to enhance clinical drug responses and avoid disease relapse.

Mesenchymal stem cells gene signature in high-risk myeloma bone marrow linked to suppression of distinct IGFBP2-expressing small adipocytes

Recent studies suggest that multiple myeloma (MM) induces proliferation and expansion of bone marrow (BM) mesenchymal stem cells (MSCs), but others showed that MM cells induce MSC senescence. To clarify the interaction between MM and MSCs, we exploited our established MSC gene signature to identify gene expression changes in myeloma MSCs and associated functional differences. Single MSCs from patients with MM had changes in expression of genes associated with cellular proliferation and senescence and a higher proportion of senescent cells and lower proliferative potential than those from age-matched healthy donors. Single MSCs from both sources heterogeneously express MSC genes associated with adipogenesis and osteoblastogenesis. We identified the gene encoding insulin-like growth factor-binding protein 2 (IGFBP2), an MSC gene commonly altered in high risk MM, as under-expressed. Morphologically, IGFBP2+ cells are underrepresented in MM BM compared to smouldering MM. Strong IGFBP2 and adiponectin co-expression was detected in a subset of small adipocytes. Co-culturing normal MSCs with myeloma cells suppressed MSC differentiation to adipocytes and osteoblasts, and reduced expression of IGFBP2 and adiponectin. Recombinant IGFBP2 blocked IGF1-mediated myeloma cell growth. Our data demonstrate that myeloma MSCs are less proliferative and that IGFBP2+ small adipocytes are a distinct mesenchymal cell population suppressed by myeloma.

NRF2 Is One of the Players Involved in Bone Marrow Mediated Drug Resistance in Multiple Myeloma

Multiple myeloma with clonal plasma expansion in bone marrow is the second most common hematologic malignancy in the world. Though the improvement of outcomes from the achievement of novel agents in recent decades, the disease progresses and leads to death eventually due to the elusive nature of myeloma cells and resistance mechanisms to therapeutic agents. In addition to the molecular and genetic basis of resistance pathomechanisms, the bone marrow microenvironment also contributes to disease progression and confers drug resistance in myeloma cells. In this review, we focus on the current state of the literature in terms of critical bone marrow microenvironment components, including soluble factors, cell adhesion mechanisms, and other cellular components. Transcriptional factor nuclear factor erythroid-derived-2-like 2 (NRF2), a central regulator for anti-oxidative stresses and detoxification, is implicated in chemoresistance in several cancers. The functional roles of NRF2 in myeloid-derived suppressor cells and multiple myeloma cells, and the potential of targeting NRF2 for overcoming microenvironment-mediated drug resistance in multiple myeloma are also discussed.

PDK1 inhibitor GSK2334470 exerts antitumor activity in multiple myeloma and forms a novel multitargeted combination with dual mTORC1/C2 inhibitor PP242

A deeper understanding of the complex pathogenesis of multiple myeloma (MM) continues to lead to novel therapeutic approaches. Prior studies suggest that 3-phosphoinositide-dependent kinase 1 (PDK1) is expressed and active, acting as a crucial regulator of molecules that are essential for myelomagenesis. In the present study, we show that GSK2334470 (GSK-470), a novel and highly specific inhibitor of PDK1, induces potent cytotoxicity in MM cell lines including Dexamethasone-resistant cell line, but not in human normal cells. Insulin-like growth factor-1 could not rescue GSK-470-induced cell death. Moreover, GSK-470 down-modulates phosphor-PDK1, thereby inhibiting downstream phosphor-AKT at Thr308 and mTOR complex 1 (mTORC1) activity. However, GSK-470 could not affect mTORC2 activity and phosphor-AKT at Ser473. RPMI 8226 and OPM-2 cells with low expression of PTEN show relative resistant to GSK-470. Knockout of PTEN by shRNA resulted in a partial reversion of GSK-470-mediated growth inhibition, whereas overexpression of PTEN enhanced myeloma cell sensitivity to GSK-470, suggesting that the sensitivity to GSK-470 is correlated with PTEN expression statue in MM cells. Combining PP242, a dual mTORC1/C2 inhibitor, with GSK-470, had greater antimyeloma activity than either one alone in vitro and in MM xenograft model established in immunodeficient mice. In particular, this combination was able to result in a complete inhibition of mTORC1/C2 and full activity of AKT. Together, these findings raise the possibility that combining PDK1 antagonist GSK-470 with mTORC1/C2 inhibitors may represent a novel strategy against MM including drug-resistant myeloma, regardless of PTEN expression status.

Microenvironment drug resistance in multiple myeloma: emerging new players

Multiple myeloma (MM) drug resistance (DR) is a multistep transformation process based on a powerful interplay between bone marrow stromal cells and MM cells that allows the latter to escape anti-myeloma therapies. Here we present an overview of the role of the bone marrow microenvironment in both soluble factors-mediated drug resistance (SFM-DR) and cell adhesion-mediated drug resistance (CAM-DR), focusing on the role of new players, namely miRNAs, exosomes and cancer-associated fibroblasts.

Monoclonal Antibody Therapies for Hematological Malignancies: Not Just Lineage-Specific Targets

Today, monoclonal antibodies (mAbs) are a widespread and necessary tool for biomedical science. In the hematological cancer field, since rituximab became the first mAb approved by the Food and Drug Administration for the treatment of B-cell malignancies, a number of effective mAbs targeting lineage-specific antigens (LSAs) have been successfully developed. Non-LSAs (NLSAs) are molecules that are not restricted to specific leukocyte subsets or tissues but play relevant pathogenic roles in blood cancers including the development, proliferation, survival, and refractoriness to therapy of tumor cells. In consequence, efforts to target NLSAs have resulted in a plethora of mAbs-marketed or in development-to achieve different goals like neutralizing oncogenic pathways, blocking tumor-related chemotactic pathways, mobilizing malignant cells from tumor microenvironment to peripheral blood, modulating immune-checkpoints, or delivering cytotoxic drugs into tumor cells. Here, we extensively review several novel mAbs directed against NLSAs undergoing clinical evaluation for treating hematological malignancies. The review focuses on the structure of these antibodies, proposed mechanisms of action, efficacy and safety profile in clinical studies, and their potential applications in the treatment of hematological malignancies.

Mechanisms of Resistance in Multiple Myeloma

Multiple myeloma (MM) is an incurable hematopoietic cancer that is characterized by malignant plasma cell infiltration of the bone marrow and/or extramedullary sites. Multi-modality approaches including "novel agents," traditional chemotherapy, and/or stem cell transplantation are used in MM therapy. Drug resistance, however, ultimately develops and the disease remains incurable for the vast majority of patients. In this chapter, we review both tumor cell-autonomous and non-autonomous (microenvironment-dependent) mechanisms of drug resistance. MM provides an attractive paradigm highlighting a number of current concepts and challenges in oncology. Firstly, identification of MM cancer stem cells and their unique drug resistance attributes may provide rational avenues towards MM eradication and cure. Secondly, the oligoclonal evolution of MM and alternation of "clonal tides" upon therapy challenge our current understanding of treatment responses. Thirdly, the success of MM "novel agents" provides exemplary evidence for the impact of therapies that target the immune and non-immune microenvironment. Fourthly, the rapid pace of drug approvals for MM creates an impetus for development of precision medicine strategies and biomarkers that promote efficacy and mitigate toxicity and cost. While routine cure of the disease remains the ultimate and yet unattainable prize, MM advances in the last 10-15 years have provided an astounding paradigm for the treatment of blood cancers in the modern era and have radically transformed patient outcomes.

IGF-I regulates HT1080 fibrosarcoma cell migration through a syndecan-2/Erk/ezrin signaling axis

Fibrosarcoma is a tumor of mesenchymal origin, originating from fibroblasts. IGF-I is an anabolic growth factor which exhibits significant involvement in cancer progression. In this study, we investigated the possible participation of syndecan-2 (SDC-2), a cell membrane heparan sulfate (HS) proteoglycan on IGF-I dependent fibrosarcoma cell motility. Our results demonstrate that SDC-2-deficient HT1080 cells exhibit attenuated IGF-I-dependent chemotactic migration (p < 0.001). SDC-2 was found to co-localize to IGF-I receptor (IGF-IR) in a manner dependent on IGF-I activity (P ≤ 0.01). In parallel, the downregulation of SDC-2 significantly inhibited both basal and due to IGF-I action ERK1/2 activation, (p < 0.001). The phosphorylation levels of ezrin (Thr567), which is suggested to act as a signaling bridge between the cellular membrane receptors and actin cytoskeleton, were strongly enhanced by IGF-I at both 1h and 24h (p < 0.05; p < 0.01). The formation of an immunoprecipitative complex revealed an association between SDC2 and ezrin which was enhanced through IGF-I action (p < 0.05). Immunoflourescence demonstrated a co-localization of IGF-IR, SDC2 and ezrin upregulated by IGF-I action. IGF-I enhanced actin polymerization and ezrin/actin specific localization to cell membranes. Finally, treatment with IGF-I strongly increased SDC2 expression at both the mRNA and protein level (p < 0.001). Therefore, we propose a novel SDC2-dependent mechanism, where SDC2 is co-localized with IGF-IR and enhances its' IGFI-dependent downstream signaling. SDC2 mediates directly IGFI-induced ERK1/2 activation, it recruits ezrin, contributes to actin polymerization and ezrin/actin specific localization to cell membranes, ultimately facilitating the progression of IGFI-dependent fibrosarcoma cell migration.

Targeting Insulin Receptor in Breast Cancer Using Small Engineered Protein Scaffolds

Insulin receptor (InsR) and the type I insulin-like growth factor (IGF1R) are homologous receptors necessary for signal transduction by their cognate ligands insulin, IGF-I and IGF-II. IGF1R mAbs, intended to inhibit malignant phenotypic signaling, failed to show benefit in patients with endocrine-resistant tumors in phase III clinical trials. Our previous work showed that in tamoxifen-resistant cells, IGF1R expression was lacking, but InsR inhibition effectively blocked growth. In endocrine-sensitive breast cancer cells, insulin was not growth stimulatory, likely due to the presence of hybrid InsR/IGF1R, which has high affinity for IGF-I, but not insulin. Combination inhibition of InsR and IGF1R showed complete suppression of the system in endocrine-sensitive breast cancer cells. To develop InsR-binding agents, we employed a small protein scaffold, T7 phage gene 2 protein (Gp2) with the long-term goal of creating effective InsR inhibitors and diagnostics. Using yeast display and directed evolution, we identified three Gp2 variants (Gp2 #1, #5, and #10) with low nanomolar affinity and specific binding to cell surface InsR. These Gp2 variants inhibited insulin-mediated monolayer proliferation in both endocrine-sensitive and resistant breast cancer, but did not downregulate InsR expression. Gp2 #5 and Gp2 #10 disrupted InsR function by inhibiting ligand-induced receptor activation. In contrast, Gp2 #1 did not block InsR phosphorylation. Notably, Gp2 #1 binding was enhanced by pretreatment of cells with insulin, suggesting a unique receptor-ligand-binding mode. These Gp2 variants are the first nonimmunoglobulin protein scaffolds to target insulin receptor and present compelling opportunity for modulation of InsR signaling. Mol Cancer Ther; 16(7); 1324-34. ©2017 AACR.