Development of a cell adhesion-based prognostic model for multiple myeloma: Insights into chemotherapy response and potential reversal of adhesion effects

Multiple myeloma (MM) is a hematologic malignancy notorious for its high relapse rate and development of drug resistance, in which cell adhesion-mediated drug resistance plays a critical role. This study integrated four RNA sequencing datasets (CoMMpass, GSE136337, GSE9782, and GSE2658) and focused on analyzing 1706 adhesion-related genes. Rigorous univariate Cox regression analysis identified 18 key prognosis-related genes, including KIF14, TROAP, FLNA, MSN, LGALS1, PECAM1, and ALCAM, which demonstrated the strongest associations with poor overall survival (OS) in MM patients. To comprehensively evaluate the impact of cell adhesion on MM prognosis, an adhesion-related risk score (ARRS) model was constructed using Lasso Cox regression analysis. The ARRS model emerged as an independent prognostic factor for predicting OS. Furthermore, our findings revealed that a heightened cell adhesion effect correlated with tumor resistance to DNA-damaging drugs, protein kinase inhibitors, and drugs targeting the PI3K/Akt/mTOR signaling pathway. Nevertheless, we identified promising drug candidates, such as tirofiban, pirenzepine, erlotinib, and bosutinib, which exhibit potential in reversing this resistance. In vitro, experiments employing NCIH929, RPMI8226, and AMO1 cell lines confirmed that MM cell lines with high ARRS exhibited poor sensitivity to the aforementioned candidate drugs. By employing siRNA-mediated knockdown of the key ARRS model gene KIF14, we observed suppressed proliferation of NCIH929 cells, along with decreased adhesion to BMSCs and fibronectin. This study presents compelling evidence establishing cell adhesion as a significant prognostic factor in MM. Additionally, potential molecular mechanisms underlying adhesion-related resistance are proposed, along with viable strategies to overcome such resistance. These findings provide a solid scientific foundation for facilitating clinically stratified treatment of MM.

Targeting CAM-DR and Mitochondrial Transfer for the Treatment of Multiple Myeloma

The prognosis of patients with multiple myeloma (MM) has improved dramatically with the introduction of new therapeutic drugs, but the disease eventually becomes drug-resistant, following an intractable and incurable course. A myeloma niche (MM niche) develops in the bone marrow microenvironment and plays an important role in the drug resistance mechanism of MM. In particular, adhesion between MM cells and bone marrow stromal cells mediated by adhesion molecules induces cell adhesion-mediated drug resistance (CAM-DR). Analyses of the role of mitochondria in cancer cells, including MM cells, has revealed that the mechanism leading to drug resistance involves exchange of mitochondria between cells (mitochondrial transfer) via tunneling nanotubes (TNTs) within the MM niche. Here, we describe the discovery of these drug resistance mechanisms and the identification of promising therapeutic agents primarily targeting CAM-DR, mitochondrial transfer, and TNTs.

CAM-DR: Mechanisms, Roles and Clinical Application in Tumors

Despite the continuous improvement of various therapeutic techniques, the overall prognosis of tumors has been significantly improved, but malignant tumors in the middle and advanced stages still cannot be completely cured. It is now evident that cell adhesion-mediated resistance (CAM-DR) limits the success of cancer therapies and is a great obstacle to overcome in the clinic. The interactions between tumor cells and extracellular matrix (ECM) molecules or adjacent cells may play a significant role in initiating the intracellular signaling pathways that are associated with cell proliferation, survival upon binding to their ligands. Recent studies illustrate that these adhesion-related factors may contribute to the survival of cancer cells after chemotherapeutic therapy, advantageous to resistant cells to proliferate and develop multiple mechanisms of drug resistance. In this review, we focus on the molecular basis of these interactions and the main signal transduction pathways that are involved in the enhancement of the cancer cells’ survival. Furthermore, therapies targeting interactions between cancer cells and their environment to enhance drug response or prevent the emergence of drug resistance will also be discussed.

Insight into Cisplatin-Resistance Signaling of W1 Ovarian Cancer Cells Emerges mTOR and HSP27 as Targets for Sensitization Strategies

The microenvironment possesses a strong impact on the tumor chemoresistance when cells bind to components of the extracellular matrix. Here we elucidate the signaling pathways of cisplatin resistance in W1 ovarian cancer cells binding to collagen type 1 (COL1) and signaling interference with constitutive cisplatin resistance in W1CR cells to discover the targets for sensitization. Proteome kinase arrays and Western blots were used to identify the signaling components, their impact on cisplatin resistance was evaluated by inhibitory or knockdown approaches. W1 cell binding to COL1 upregulates integrin-associated signals via FAK/PRAS40/mTOR, confirmed by β1-integrin (ITGB1) knockdown. mTOR appears as key for resistance, its blockade reversed COL1 effects on W1 cell resistance completely. W1CR cells compensate ITGB1-knockdown by upregulation of discoidin domain receptor 1 (DDR1) as alternative COL1 sensor. COL1 binding via DDR1 activates the MAPK pathway, of which JNK1/2 appears critical for COL1-mediated resistance. JNK1/2 inhibition inverts COL1 effects in W1CR cells, whereas intrinsic cisplatin resistance remained unaffected. Remarkably, knockdown of HSP27, another downstream MAPK pathway component overcomes intrinsic resistance completely sensitizing W1CR cells to the level of W1 cells for cisplatin cytotoxicity. Our data confirm the independent regulation of matrix-induced and intrinsic chemoresistance in W1 ovarian cancer cells and offer novel targets for sensitization.

Oroxylin A reversed Fibronectin-induced glioma insensitivity to Temozolomide by suppressing IP3R1/AKT/β-catenin pathway

AIMS

Cell adhesion mediated-drug resistance (CAM-DR) is one of main reasons for. the limitation to chemotherapy, but the underlying mechanism remains unclear in glioma. In this study, we investigated the mechanism of CAM-DR induced by Fibronectin (Fn). Besides, we studied the reversal effect of Oroxylin A, a natural flavonoid extracted from Scutellaria radix, on Temozolomide (TMZ) insensitivity of glioma cells.

MAIN METHODS

Human Fn protein was used to mimic cell adhesion model and investigate its effect on the insensitivity of glioma cells to TMZ. Moreover, Oroxylin A was studied regarding its reversal effect on TMZ insensitivity of glioma via multiple molecular biological methods such as MTT, cell apoptosis assay, siRNA transfection, western blot, immunofluorescence assay.

KEY FINDINGS

Fn could decrease the apoptosis-inducing effect of TMZ and led to the CAM-DR in glioma cells. Further studies showed that up-regulations of IP₃R1 and intracellular Ca²⁺ level induced the activation of AKT kinase which increased the phosphorylation of GSK-3β and subsequently caused the entry of β-catenin into the nucleus. Knocking down IP₃R1 significantly improved the sensitivity of glioma cells to TMZ. Meanwhile, after treatment with low-toxic concentration of Oroxylin A, the apoptosis induced by TMZ under Fn condition increased dramatically. Furthermore, our results revealed that Oroxylin A markedly inhibited the expression of IP₃R1 and the activation of AKT/β-catenin pathway.

SIGNIFICANCE

Oroxylin A could reverse the insensitivity of TMZ via suppressing IP₃R1/AKT/β-catenin pathway and it might be helpful for enhancing the anti-cancer effect of TMZ in glioma.

Runt-related transcription factor 2 influences cell adhesion-mediated drug resistance and cell proliferation in B-cell non-Hodgkin's lymphoma and multiple myeloma

Several lines of evidence show that RUNX2 as a transcription factor is closely involved in carcinogenesis in a variety of human cancers. Cell adhesion-mediated drug resistance (CAM-DR) is an important part of the mechanism underlying drug resistance in hematological tumors. In this study, we investigated the biological function of RUNX2 in B-cell Non-Hodgkin's lymphoma (B-NHL) and multiple myeloma (MM). We assessed the expression of RUNX2 in suspension and adhesion model by western blot in B-NHL and MM. Adhesion assay, flow cytometry and CCK-8 were utilized to examine the role and mechanism of RUNX2 in CAM-DR and proliferation in B-NHL and MM. RUNX2 was highly expressed in adherent B-NHL and MM cells compared to suspension cells, and knockdown the expression of RUNX2 could reverse CAM-DR. Besides, RUNX2 could promote the proliferation of B-NHL and MM cells. Furthermore, RUNX2 participated the process of CAM-DR and proliferation by regulating the AKT/GSK-3β pathway. Developing RUNX2 inhibitor may be a possible strategy for drug resistance.

Mechanisms of Matrix-Induced Chemoresistance of Breast Cancer Cells-Deciphering Novel Potential Targets for a Cell Sensitization

Tumor cell binding to microenvironment components such as collagen type 1 (COL1) attenuates the sensitivity to cytotoxic drugs like cisplatin (CDDP) or mitoxantrone (MX), referred to as cell adhesion mediated drug resistance (CAM-DR). CAM-DR is considered as the onset for resistance mutations, but underlying mechanisms remain elusive. To evaluate CAM-DR as target for sensitization strategies, we analyzed signaling pathways in human estrogen-positive MCF-7 and triple-negative MDA-MB-231 breast cancer cells by western blot, proteome profiler array and TOP-flash assay in presence of COL1. β1-Integrins, known to bind COL1, appear as key for mediating COL1-related resistance in both cell lines that primarily follows FAK/PI3K/AKT pathway in MCF-7, and MAPK pathway in MDA-MB-231 cells. Notably, pCREB is highly elevated in both cell lines. Consequently, blocking these pathways sensitizes the cells evidently to CDDP and MX treatment. Wnt signaling is not relevant in this context. A β1-integrin knockdown of MCF-7 cells (MCF-7-β1-kd) reveals a signaling shift from FAK/PI3K/AKT to MAPK pathway, thus CREB emerges as a promising primary target for sensitization in MDA-MB-231, and secondary target in MCF-7 cells. Concluding, we provide evidence for importance of CAM-DR in breast cancer cells and identify intracellular signaling pathways as targets to sensitize cells for cytotoxicity treatment regimes.

Various Signaling Pathways in Multiple Myeloma Cells and Effects of Treatment on These Pathways

Multiple myeloma (MM) results from malignancy in plasma cells and occurs at ages > 50 years. MM is the second most common hematologic malignancy after non-Hodgkin lymphoma, which constitutes 1% of all malignancies. Despite the great advances in the discovery of useful drugs for this disease such as dexamethasone and bortezomib, it is still an incurable malignancy owing to the development of drug resistance. The tumor cells develop resistance to apoptosis, resulting in greater cell survival, and, ultimately, develop drug resistance by changing the various signaling pathways involved in cell proliferation, survival, differentiation, and apoptosis. We have reviewed the different signaling pathways in MM cells. We reached the conclusion that the most important factor in the drug resistance in MM patients is caused by the bone marrow microenvironment with production of adhesion molecules and cytokines. Binding of tumor cells to stromal cells prompts cytokine production of stromal cells and launches various signaling pathways such as Janus-activated kinase/signal transduction and activator of transcription, Ras/Raf/MEK/mitogen-activated protein kinase, phosphatidyl inositol 3-kinase/AKT, and NF-KB, which ultimately lead to the high survival rate and drug resistance in tumor cells. Thus, combining various drugs such as bortezomib, dexamethasone, lenalidomide, and melphalan with compounds that are not common, including CTY387, LLL-12, OPB31121, CNTO328, OSI-906, FTY720, triptolide, and AV-65, could be one of the most effective treatments for these patients.

The PI3Kδ Inhibitor Idelalisib Inhibits Homing in an in Vitro and in Vivo Model of B ALL

The quest continues for targeted therapies to reduce the morbidity of chemotherapy and to improve the response of resistant leukemia. Adhesion of acute lymphoblastic leukemia (ALL) cells to bone marrow stromal cells triggers intracellular signals that promote cell-adhesion-mediated drug resistance (CAM-DR). Idelalisib, an U.S. Food and Drug Administration (FDA)-approved PI3Kδ-specific inhibitor has been shown to be effective in CLL in down-regulating p-Akt and prolonging survival in combination with Rituximab; herein we explore the possibility of its use in B ALL and probe the mechanism of action. Primary B ALL in contact with OP9 stromal cells showed increased p-Akt^ser473. Idelalisib decreased p-Akt in patient samples of ALL with diverse genetic lesions. Addition of idelalisib to vincristine inhibited proliferation when compared to vincristine monotherapy in a subset of samples tested. Idelalisib inhibited ALL migration to SDF-1α in vitro and blocked homing of ALL cells to the bone marrow in vivo. This report tests PI3Kδ inhibitors in a more diverse group of ALL than has been previously reported and is the first published report of idelalisib inhibiting homing of ALL cells to bone marrow. Our data support further pre-clinical evaluation of idelalisib for the therapy of B ALL.

The cancer cell adhesion resistome: mechanisms, targeting and translational approaches

Cell adhesion-mediated resistance limits the success of cancer therapies and is a great obstacle to overcome in the clinic. Since the 1990s, where it became clear that adhesion of tumor cells to the extracellular matrix is an important mediator of therapy resistance, a lot of work has been conducted to understand the fundamental underlying mechanisms and two paradigms were deduced: cell adhesion-mediated radioresistance (CAM-RR) and cell adhesion-mediated drug resistance (CAM-DR). Preclinical work has evidently demonstrated that targeting of integrins, adapter proteins and associated kinases comprising the cell adhesion resistome is a promising strategy to sensitize cancer cells to both radiotherapy and chemotherapy. Moreover, the cell adhesion resistome fundamentally contributes to adaptation mechanisms induced by radiochemotherapy as well as molecular drugs to secure a balanced homeostasis of cancer cells for survival and growth. Intriguingly, this phenomenon provides a basis for synthetic lethal targeted therapies simultaneously administered to standard radiochemotherapy. In this review, we summarize current knowledge about the cell adhesion resistome and highlight targeting strategies to override CAM-RR and CAM-DR.

Upregulation of ADAM12 contributes to accelerated cell proliferation and cell adhesion-mediated drug resistance (CAM-DR) in Non-Hodgkin's Lymphoma

OBJECTIVE

ADAM12 is a member of a disintegrin and metalloproteinase family and has been reported to participate in the development of variety of tumors. However, the role of ADAM12 in Non-Hodgkin Lymphoma (NHL) has not been investigated. The present study was undertaken to determine the expression and biologic function of ADAM12 in human NHL.

METHODS

First, we constructed a model of cell adhesion in NHL, the mRNA, and protein level of ADAM12 in suspension and the adhesion model was analyzed by RT-PCR and western blot. Then, flow cytometry assay and western blot were used to investigate the mechanism of ADAM12 in the proliferation of NHL cells. In vitro, after using siRNA interfering ADAM12 expression, we performed adhesion assay and cell viability assay to determine the effect of ADAM12 on adhesive rate and drug sensitivity.

RESULTS

ADAM12 was lowly expressed in suspended cells and highly expressed in adherent NHL cells. In addition, ADAM12 was positively correlated with the proliferation and apoptosis of NHL cells by regulating the expression of p-AKT and p-GSK-3β. Furthermore, ADAM12 promoted cell adhesion-mediated drug resistance (CAM-DR) in DLBCL via AKT signaling pathway.

CONCLUSION AND DISCUSSION

Our data support a role for ADAM12 in NHL cell proliferation, adhesion, and drug resistance, and it may pave the way for a novel therapeutic approach for CAM-DR in NHL.

EphA4 promotes cell proliferation and cell adhesion-mediated drug resistance via the AKT pathway in multiple myeloma

Eph receptor A4 (EphA4), a member of the erythropoietin-producing hepatocellular (Eph) family, has been reported to upregulate in several tumors. However, the role of EphA4 in multiple myeloma has not been clarified yet. In this study, we found that EphA4 promoted proliferation of multiple myeloma cells via the regulation of cell cycle. Besides, EphA4 was closely related to cell adhesion of multiple myeloma cells and promoted cell adhesion-mediated drug resistance by enhancing the phosphorylation levels of Akt (p-AKT) expression in multiple myeloma. More interestingly, we discovered that EphA4 can interact with cyclin-dependent kinase 5 (CDK5) and regulate its expression in multiple myeloma. CDK5 has been reported to be overexpressed in multiple myeloma which mediated bortezomib resistance and also participated in AKT pathway. And we have also proved the fact. So, we supposed that EphA4 interacted with CDK5 and promoted its expression which in turn enhanced p-AKT expression and promoted cell adhesion-mediated drug resistance in multiple myeloma. Therefore, this study clarifies the molecular mechanism of cell adhesion-mediated drug resistance and may be useful in identifying potential target for treatment of multiple myeloma.

RBQ3 participates in multiple myeloma cell proliferation, adhesion and chemoresistance

Cell adhesion mediated drug resistance (CAM-DR) is a major factor that impedes the effect of chemotherapy in multiple myeloma (MM). RBQ3, which is a RB-binding protein, played a crucial role in cell cycle process. Here, we reported that RBQ3 expression was increased gradually during the proliferation process of myeloma cells. Knocking down of RBQ3 resulted in cell cycle arrest in G1 phase and increased myeloma cells adherent to fibronectin or bone marrow stromal cells (BMSCs). Furthermore, silencing of RBQ3 reduced sensitivity to chemotherapeutic drugs in myeloma cell lines adherent to BMSCs and reduced two apoptotic marker proteins cleaved caspase-3 and cleaved PARP expression. Besides, we also found that RBQ3 participated in MAPK/ERK signal transduction pathway. In summary, these results may shed new insights into the role of RBQ3 in the development of multiple myeloma.

Pyruvate kinase isoform M2 (PKM2) participates in multiple myeloma cell proliferation, adhesion and chemoresistance

Cell adhesion mediated drug resistance (CAM-DR) remains the major barrier in human multiple myeloma (MM) therapy. In the present study, we aimed at investigating the role of pyruvate kinase isoform M2 (PKM2) in MM CAM-DR. We determined that PKM2 expression was positively correlated with cell proliferation and knockdown of PKM2 contributed to the increased cell adhesion rate in MM. The enhancement in the adhesion of MM cells to fibronectin or the bone marrow stroma cell line HS-5 cells translated to an increased CAM-DR phenotype. Importantly, we showed that this CAM-DR phenotype was correlated with the phosphorylation of Akt and ERK in MM cells. Taken together, our data shed new light on the molecular mechanism of CAM-DR in MM, and targeting PKM2 may be a novel therapeutic approach for improving the effectiveness of chemotherapy in MM.

Lewis y enhances CAM-DR in ovarian cancer cells by activating the FAK signaling pathway and upregulating Bcl-2/Bcl-XL expression

Oligosaccharides on the surface of adhesion molecules may contribute to the process of CAM-DR. To investigate the role of the Lewis y antigen in this process, we established a cell adhesion model mediated by the integrin α5β1-FN interaction in the ovarian cancer cell line, RMG-1-hFUT, which highly expresses Lewis y by transfection with α1,2-fucosyltransferase into RMG-1 cells. Our results indicate that the rates of carboplatin-induced apoptosis and necrosis are reduced in FN-adhered tumor cells, and carboplatin resistance is significantly decreased in the presence of anti-Lewis y antibody. CAM-DR in tumor cells has been correlated with elevated expression of the nuclear anti-apoptotic proteins Bcl-2 and Bcl-XL. Lewis y promotes the expression of the Bcl-2 and Bcl-XL genes by activating the focal adhesion kinase signaling pathway and accelerating their transcription. Thus, Lewis y leads to inhibition of apoptosis and enhancement of CAM-DR by activation of the FAK signaling pathway and upregulation of Bcl-2/Bcl-XL expression in ovarian cancer cell lines.

Histamine-releasing factor/translationally controlled tumor protein plays a role in induced cell adhesion, apoptosis resistance and chemoresistance in non-Hodgkin lymphomas

Mounting evidence has proved that cellular adhesion confers resistance to chemotherapy in multiple lymphomas. The molecular mechanism underlying cell adhesion-mediated drug resistance (CAM-DR) is, however, poorly understood. In this study, we investigated the expression and biologic function of histamine-releasing factor (HRF) in non-Hodgkin lymphomas (NHLs). Clinically, by immunohistochemistry analysis we observed obvious up-regulation of HRF in NHLs including diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL) and natural killer (NK)/T-cell lymphoma. Functionally, overexpression and knockdown of HRF demonstrated the antiapoptotic effect of HRF in NHL cells, which may be associated with activation of the p-CREB/BCL-2 signaling pathway. Moreover, cell adhesion assay demonstrated that adhesion to fibronectin (FN) or HS-5 up-regulated HRF expression, while knockdown of HRF resulted in decreased cell adhesion, which led to reversed CAM-DR. Our finding supports the role of HRF in NHL cell apoptosis, adhesion and drug resistance, and may provide a clinical therapeutic target for CAM-DR in NHL.

Membranous expressions of Lewis y and CAM-DR-related markers are independent factors of chemotherapy resistance and poor prognosis in epithelial ovarian cancer

BACKGROUND

Chemotherapy resistance is a common problem faced by patients diagnosed with epithelial ovarian cancer (EOC). Currently there are no specific or sensitive clinical biomarkers that maybe implemented to identify chemotherapy resistance and give insight to prognosis. The aim of this study is to investigate the roles of Lewis y antigen and the markers associated with cell-adhesion-mediated drug resistance (CAM-DR) in patients with EOC.

METHODS

92 EOC patients who were treated with systemic chemotherapy after cytoreductive surgery were included in this analysis. Patients were divided into two groups, chemotherapy sensitive (n = 56) and resistant (n = 36). Immunohistochemical (IHC) staining for Lewis y and CAM-DR-related cell surface proteins including CD44, CD147, HE4 (Human epididymis protein 4), integrin α5, β1, αv and β3 were conducted on tissues collected during primary debulking surgery. Using multivariate logistic regressions, IHC results were compared to clinical variables and chemotherapy resistance to determine possible correlations. The relationships between IHC expression and progression-free survival (PFS) and overall survival (OS) were analyzed using Kaplan-Meier method and Cox regression analysis.

RESULTS

Membranous expression of Lewis y and all these CAM-DR-related markers were significantly higher in the resistant group than that of the sensitive group (all P < 0.01). Multivariate regression analysis revealed that high expression of Lewis y, CD44, HE4, integrin α5 and β1 as well as advanced FIGO stage were independent risk factors for chemotherapy resistance (all P < 0.05). Advanced FIGO stage, lymph node metastasis and high expression of Lewis y, CD44, CD147, HE4, integrin α5, β1 were associated with a shorter PFS and OS (all P < 0.05). Moreover, multivariate COX analysis demonstrated that the following variates were independent predictors of worse PFS and OS survival: late FIGO stage (P = 0.013, 0.049), high expressions of Lewis y (P = 0.010, 0.036), HE4 (P = 0.006, 0.013) and integrin β1 (PFS, P = 0.003), integrin α5 (OS, P = 0.019).

CONCLUSION

Membranous expression of Lewis y and CAM-DR-related markers including CD44, CD147, HE4, integrin α5, β1, αv and β3 are associated with the development of chemotherapy resistance. High expression of Lewis y antigen and CAM-DR-related markers including CD44, CD147, HE4, integrin α5 and β1 are independent markers for PFS and OS, in which Lewis y and HE4 are the most significant.

MGr1-Ag/37LRP induces cell adhesion-mediated drug resistance through FAK/PI3K and MAPK pathway in gastric cancer

It is well known that tumor microenvironment plays a vital role in drug resistance and cell adhesion-mediated drug resistance (CAM-DR), a form of de novo drug resistance. In our previous study, we reported that MGr1-Ag/37LRP ligation-induced adhesion participated in protecting gastric cancer cells from a number of apoptotic stimuli caused by chemotherapeutic drugs. Further study suggested that MGr1-Ag could prompt CAM-DR through interaction with laminin. However, the MGr1-Ag-initiated intracellular signal transduction pathway is still unknown. In this study, our experimental results showed that gastric cancer MDR cell lines mediated CAM-DR through upregulation of Bcl-2 by MGr1-Ag interaction with laminin. Further study found that, as a receptor of ECM components, MGr1-Ag/37LRP may activate the downstream signal pathway PI3K/AKT and MAPK/ERK through interaction with phosphorylated FAK. Moreover, the sensitivity to chemotherapeutic drugs could be significantly enhanced by inhibiting MGr1-Ag/37LRP expression through mAbs, siRNA, and antisense oligonucleotide. According to these results, we concluded that the FAK/PI3K and MAPK signal pathway plays an important role in MGr1-Ag-mediated CAM-DR in gastric cancer. MGr1-Ag/37LRP might be a potential effective reversal target to MDR in gastric cancer.

The role of the orphan G protein-coupled receptor 37 (GPR37) in multiple myeloma cells

The orphan G protein-coupled receptor 37 (GPR37) is homologous to endothelin (ETB-R) and bombesin (GRP-R, NMB-R) receptors. The present study was undertaken to determine the expression and functional significance of GPR37 in human multiple myeloma (MM). We found that GPR37 was lowly expressed in MM cell adhesion model and highly expressed in proliferating cells. In vitro, meddling with the expression of GPR37 affected the CAM-DR by regulating the ability of cell adhesion and the activity of Akt and ERK in MM cells. Further studies indicated the positive role of GPR37 in the proliferation of MM cells.

Nanomedicine therapeutic approaches to overcome cancer drug resistance

Nanomedicine is an emerging form of therapy that focuses on alternative drug delivery and improvement of the treatment efficacy while reducing detrimental side effects to normal tissues. Cancer drug resistance is a complicated process that involves multiple mechanisms. Here we discuss the major forms of drug resistance and the new possibilities that nanomedicines offer to overcome these treatment obstacles. Novel nanomedicines that have a high ability for flexible, fast drug design and production based on tumor genetic profiles can be created making drug selection for personal patient treatment much more intensive and effective. This review aims to demonstrate the advantage of the young medical science field, nanomedicine, for overcoming cancer drug resistance. With the advanced design and alternative mechanisms of drug delivery known for different nanodrugs including liposomes, polymer conjugates, micelles, dendrimers, carbon-based, and metallic nanoparticles, overcoming various forms of multi-drug resistance looks promising and opens new horizons for cancer treatment.