Brain derived neurotropic factor single nucleotide polymorphism Val66Met and serum protein levels are associated with development of vincristine‐induced peripheral neuropathy in patients with lymphoma

Biomarkers of Chemotherapy-Induced Peripheral Neuropathy: Current Status and Future Directions

Chemotherapy induced peripheral neuropathy (CIPN) is an often severe and debilitating complication of multiple chemotherapeutic agents that can affect patients of all ages, across cancer diagnoses. CIPN can persist post-therapy, and significantly impact the health and quality of life of cancer survivors. Identifying patients at risk for CIPN is challenging due to the lack of standardized objective measures to assess for CIPN. Furthermore, there are no approved preventative treatments for CIPN, and therapeutic options for CIPN remain limited once it develops. Biomarkers of CIPN have been studied but are not widely used in clinical practice. They can serve as an important clinical tool to identify individuals at risk for CIPN and to better understand the pathogenesis and avenues for treatment of CIPN. Here we review promising biomarkers of CIPN in humans and their clinical implications.

Brain-derived neurotrophic factor in hematological malignancies: From detrimental to potentially beneficial

Emerging studies have highlighted brain-derived neurotrophic factor (BDNF), a neuronal growth factor abundant in the peripheral blood, and its tyrosine kinase receptor TRKB, as onco-genes and proteins that support the survival of malignant hematological cells. In contrast, other researchers reported on a favorable association between BDNF blood levels and prognosis, chemotherapy response and neurological side effects in patients with hematological malignancies. Here, we review the accumulated data regarding the expression of BDNF and its receptors in normal hematopoietic and lymphatic cells and tissue. In addition, in-vitro experiments, animal models and human sample studies that investigated the role of BDNF and its receptors in hematological malignancies are discussed. Finally, directions for future research aimed at revealing the mechanisms underlying the protective effect of BDNF in patients with these diseases are suggested.

Low brain-derived neurotrophic factor protein levels and single-nucleotide polymorphism Val66Met are associated with peripheral neuropathy in type II diabetic patients

BACKGROUND

Studies by our group demonstrated brain-derived neurotrophic factor (BDNF) levels in blood and BDNF-Val66met-SNP as potential biomarkers in chemotherapy-induced peripheral neuropathy. Here, we evaluate symptoms of peripheral neuropathy (PN) and depression in patients with type II diabetes mellitus in search of an association with serum BDNF levels and the Val66Met-SNP.

METHODS

In total, 90 patients enrolled in the study; 23 (25.6%) had known PN, as determined by nerve conduction studies (NCS-PN), and 67 (74.4%) were not diagnosed with PN (U-PN). PN symptoms were assessed and graded in these groups using the total neuropathy score (TNSr) and DN4 scales. Small nerve fiber testing of sensitivity thresholds to cold, warm and hot pain signals was performed using the Q-sense device. Depression was assessed using the PHQ9 questionnaire. BDNF protein levels and Val66Met-SNP were determined with ELISA and Sanger sequencing, respectively.

RESULTS

NCS-PN patients showed lower serum BDNF levels alongside significantly higher TNSr, DN4 and PHQ9 scores and lower hot pain sensitivity thresholds as compared to U-PN patients. Patients with Met-BDNF-SNP showed increased TNSr scores and lower hot pain sensitivity thresholds as compared to patients with Val-BDNF-SNP. Depression showed a weaker correlation with sensitivity thresholds to hot pain signals as compared to TNSr and DN4 scores.

CONCLUSIONS

Diminished peripheral BDNF resources and Met-BDNF-SNP genotype are associated with augmented symptoms of PN in patients with type II diabetes mellitus. Sensitivity thresholds to hot pain signals may be less influenced by depression and possibly more accurately detect PN symptoms in diabetic patients.

Genetic polymorphisms and vincristine-induced peripheral neuropathy in patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone therapy

Vincristine (VCR)-induced peripheral neuropathy (VIPN) is a common and life-long toxicity in lymphoma patients receiving current standard chemotherapy. The association between VIPN and genetic polymorphisms is largely unknown in adult lymphoma patients. To examine the possible relationship between known genetic polymorphisms in patients with pediatric acute lymphoblastic leukemia and incidence of VIPN in adult patients with B cell lymphoma, we examined CEP72 rs924607, ETAA1 rs17032980, MTNR1B rs12786200, CYP3A5 rs776746, rs7963521, and rs1045644 genetic polymorphisms in samples from 56 adult patients with B-cell lymphoma who received rituximab, cyclophosphamide, doxorubicin, VCR, and prednisone (R-CHOP) chemotherapy. Mutation analysis was performed by direct sequencing. The median age was 65 years (range 30-79). The median cumulative dose of VCR was 12 mg (range 2-16). VIPN was documented in 42 patients (75%), and 9 (16%) had grade 2-4 VIPN. Age, impaired glucose tolerance, number of cycles of R-CHOP, and VCR cumulative dose were not associated with incidence of VIPN. There was no association between the incidence of grade 2-4 or any grade VIPN and these six genetic polymorphisms. These results indicate that CEP72, MTNR1B, ETAA1, CYP3A5, rs7963521, and rs1045644 genetic polymorphisms are not associated with VIPN in patients with B-cell lymphoma who received R-CHOP.

Prediction of Chemotherapy-Induced Peripheral Neuropathy in Patients with Lymphoma and Myeloma: the Roles of Brain-Derived Neurotropic Factor Protein Levels and A Gene Polymorphism

Background and Purpose

Brain-derived neurotrophic factor (BDNF) is a neuronal growth factor that plays an essential role in the maintenance of the nervous system. We have evaluated the peripheral blood protein levels of BDNF and the valine-to-methionine substitution at codon 66 (Val66Met) single-nucleotide polymorphism (SNP) as potential biomarkers for the early recognition of chemotherapy-induced peripheral neuropathy (CIPN) in non-Hodgkin lymphoma and multiple myeloma patients.

Methods

CIPN was assessed in 45 patients at the diagnosis and during vincristine or bortezomib-based therapy using objective [reduced version of the Total Neuropathy Score (TNSr)] and subjective (FACT-GOG-NTx) tools. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9) questionnaire. BDNF protein levels and the Val66Met SNP were determined using ELISA and Sanger sequencing.

Results

The pretreatment BDNF protein level was inversely correlated with the maximum TNSr, FACT-GOG-NTx, and PHQ-9 scores in both genotypes. BDNF patients with the Val/Val genotype demonstrated significantly higher maximum FACT-GOG-NTx and PHQ-9 scores than those with the Val/Met and Met/Met genotypes (Met-BNDF carriers). Correlations between PHQ-9 and TNSr score were found only in Met-BDNF carriers, suggesting that peripheral neuropathy and depression coincide in Met-BDNF carriers.

Conclusions

Determining the BDNF protein levels before initiating chemotherapy might be a useful tool for CIPN risk assessment and preemptive dose modification. The present data should be validated in larger studies that include other neurotoxic agents.