Income-Related Inequality Changes in Osteoarthritis First-Line Interventions: A Cohort Study.

OBJECTIVE: To examine income-related inequality changes in the outcomes of an osteoarthritis (OA) first-line intervention. DESIGN: Retrospective cohort study. SETTING: Swedish health care system. PARTICIPANTS: We included 115,403 people (age: 66.2±9.7 years; females 67.8%; N=115,403) with knee (67.8%) or hip OA (32.4%) recorded in the "Swedish Osteoarthritis Registry" (SOAR). INTERVENTIONS: Exercise and education. MAIN OUTCOME MEASURES: Erreygers' concentration index (E) measured income-related inequalities in "Pain intensity," "Self-efficacy," "Use of NSAIDs," and "Desire for surgery" at baseline, 3-month, and 12-month follow-ups and their differences over time. E-values range from -1 to +1 if the health variables are more concentrated among people with lower or higher income. Zero represents perfect equality. We used entropy balancing to address demographic and outcome imbalances and bootstrap replications to estimate confidence intervals for E differences over time. RESULTS: Comparing baseline to 3 months, "pain" concentrated more among individuals with lower income initially (E=-0.027), intensifying at 3 months (difference with baseline: E=-0.011 [95% CI: -0.014; -0.008]). Similarly, the "Desire for surgery" concentrated more among individuals with lower income initially (E=-0.009), intensifying at 3 months (difference with baseline: E=-0.012 [-0.018; -0.005]). Conversely, "Self-efficacy" concentrated more among individuals with higher income initially (E=0.058), intensifying at 3 months (difference with baseline: E=0.008 [0.004; 0.012]). Lastly, the "Use of NSAIDs" concentrated more among individuals with higher income initially (E=0.068) but narrowed at 3 months (difference with baseline: E=-0.029 [-0.038; -0.021]). Comparing baseline with 12 months, "pain" concentrated more among individuals with lower income initially (E=-0.024), intensifying at 12 months (difference with baseline: E=-0.017 [-0.022; -0.012]). Similarly, the "Desire for surgery" concentrated more among individuals with lower income initially (E=-0.016), intensifying at 12 months (difference with baseline: E=-0.012 [-0.022; -0.002]). Conversely, "Self-efficacy" concentrated more among individuals with higher income initially (E=0.059), intensifying at 12 months (difference with baseline: E=0.016 [0.011; 0.021]). The variable 'Use of NSAIDs' was not recorded in the SOAR at 12-month follow-up. CONCLUSION: Our results highlight the increase of income-related inequalities in the SOAR over time.

Perspectives on health care and self-management of osteoarthritis among patients who desire surgery: A qualitative interview study.

BACKGROUND: Expressing a desire for surgery before participating in first-line osteoarthritis (OA) interventions (patient education and exercise therapy) has been shown to contribute to poorer outcomes from the interventions, but we lack knowledge on how these patients reflect on health care and self-management of OA. OBJECTIVES: To explore and describe patients' perspectives of health care and self-management of OA among those expressing a desire for surgery before participating in first-line OA interventions. METHODS: Sixteen patients with hip or knee OA referred to participate in a standardized first-line OA intervention program in primary health care in Sweden were included in the study. We used individual semi-structured interviews to collect data, which were analyzed using inductive qualitative content analysis. RESULTS: One theme of meaning "A multifaceted picture of needs, expectations, and individual choices" and five categories were identified as perspectives from the participants regarding health care and self-management of OA: 1) lacking control and needing support; 2) standing alone in an unsupportive environment; 3) going with the flow; 4) having expectations; and 5) taking ownership. CONCLUSION: Patients who express a desire for surgery before participating in first-line interventions for OA are not a homogeneous group. They describe a broad range of perspectives on how they reason and reflect on health care and self-management of OA based on their own needs, expectations, and choices. Findings from this study strengthen insights on the importance of exploring the patient's perspectives and individualizing OA interventions to achieve the lifestyle changes that first-line interventions strive to accomplish.

What Factors Identified in Initial Osteoarthritis Management Are Associated With Poor Patient-reported Outcomes After THA? A Register-based Study.

BACKGROUND: Some patients report long-term pain or no improvement in health-related quality of life (HRQoL) or are dissatisfied after THA. However, factors associated with these poorer patient-reported outcomes after surgery are inconsistent and have typically been studied in the late phase of hip osteoarthritis (OA) among patients already eligible for surgery. Earlier identification of risk factors would provide time to address modifiable factors, helping to improve patients' pain, HRQoL, and satisfaction after surgery and reduce the burden on orthopaedic clinics by referring patients who are better prepared for surgery. QUESTIONS/PURPOSES: We analyzed data from patients with hip OA referred to a first-line OA intervention program in primary healthcare at a stage when they had not been referred for THA, and asked: (1) What percentage of patients who proceed to THA report lack of improvement in pain, lack of improvement in HRQoL as measured by the EQ-5D, or are not satisfied with surgery 1 year after THA? (2) What associations exist between baseline factors at referral to this first-line OA intervention program and these poorer patient-reported outcomes 1 year after THA? METHODS: We included 3411 patients with hip OA (mean age 67 ± 9 years, 63% [2160 of 3411] women) who had been referred for first-line OA interventions between 2008 and 2015 and subsequently underwent THA for OA. All patients were initially identified through the Swedish Osteoarthritis Register, which follows and evaluates patients in a standardized national first-line OA intervention program. Then, we identified those who were also registered in the Swedish Arthroplasty Register with a THA during the study period. We included only those with complete patient-reported outcome measures for pain, HRQoL, and satisfaction preoperatively and 1-year postoperatively, representing 78% (3411 of 4368) of patients, who had the same baseline characteristics as nonrespondents. Multiple logistic regression was used to assess the associations between 14 baseline factors and the aforementioned patient-reported outcomes of pain, HRQoL, and satisfaction 1 year after THA, adjusted for all included factors. RESULTS: Five percent (156 of 3411) of the study population lacked improvement in pain, 11% (385 of 3411) reported no improvement in HRQoL, and 10% (339 of 3411) reported they were not satisfied with surgery 1 year after THA. Charnley Class C (multiple-joint OA or another condition that affects the ability to walk) was associated with all outcomes: lack of improvement in pain (OR 1.84 [95% CI 1.24 to 2.71]; p = 0.002), lack of improvement in HRQoL (OR 1.83 [95% CI 1.42 to 2.36]; p < 0.001), and not being satisfied (OR 1.40 [95% CI 1.07 to 1.82]; p = 0.01). Older age was associated with a lack of improvement in pain (OR per year 1.03 [95% CI 1.01 to 1.05]; p = 0.02), lack of improvement in HRQoL (OR per year 1.04 [95% CI 1.03 to 1.06]; p < 0.001), and not being satisfied (OR per year 1.03 [95% CI 1.01 to 1.05]; p < 0.001). Depression was associated with a lack of improvement in pain (OR 1.54 [95% CI 1.00 to 2.35]; p = 0.050) and with not being satisfied (OR 1.50 [95% CI 1.11 to 2.04]; p = 0.01) but not with a lack of improvement in HRQoL (OR 1.04 [95% CI 0.76 to 1.43]; p = 0.79). Having four or more comorbidities was associated with a lack of improvement in HRQoL (OR 2.08 [95% CI 1.39 to 3.10]; p < 0.001) but not with a lack of improvement in pain and not being satisfied. CONCLUSION: The results of this study showed that older age, Charley Class C, and depression in patients with first-line OA interventions were risk factors associated with poorer outcomes regarding pain, HRQoL, and satisfaction after THA. Screening patients with hip OA for depression early in the disease course would provide increased time to optimize treatments and may contribute to better patient-reported pain, HRQoL, and satisfaction after future THA. Further research should focus on identifying the optimal time for surgery in patients with depression, as well as what targeted interventions for depression can improve outcome of surgery in these patients. LEVEL OF EVIDENCE: Level III, therapeutic study.

Factors Associated With Adherence to a Supervised Exercise Intervention for Osteoarthritis: Data From the Swedish Osteoarthritis Registry.

OBJECTIVE: To explore how lifestyle and demographic, socioeconomic, and disease-related factors are associated with supervised exercise adherence in an osteoarthritis (OA) management program and the ability of these factors to explain exercise adherence. METHODS: A cohort register-based study on participants from the Swedish Osteoarthritis Registry who attended the exercise part of a nationwide Swedish OA management program. We ran a multinomial logistic regression to determine the association of exercise adherence with the abovementioned factors. We calculated their ability to explain exercise adherence with the McFadden R2 . RESULTS: Our sample comprises 19,750 participants (73% female, mean ± SD age 67 ± 8.9 years). Among them, 5,862 (30%) reached a low level of adherence, 3,947 (20%) a medium level, and 9,941 (50%) a high level. After a listwise deletion, the analysis was run on 16,685 participants (85%), with low levels of adherence as the reference category. Some factors were positively associated with high levels of adherence, such as older age (relative risk ratio [RRR] 1.01 [95% confidence interval (95% CI) 1.01-1.02] per year), and the arthritis-specific self-efficacy (RRR 1.04 [95% CI 1.02-1.07] per 10-point increase). Others were negatively associated with high levels of adherence, such as female sex (RRR 0.82 [95% CI 0.75-0.89]), having a medium (RRR 0.89 [95% CI 0.81-0.98] or a high level of education (RRR 0.84 [95% CI 0.76-0.94]). Nevertheless, the investigating factors could explain 1% of the variability in exercise adherence (R2 = 0.012). CONCLUSION: Despite the associations reported above, the poorly explained variability suggests that strategies based on lifestyle and demographic, socioeconomic, and disease-related factors are unlikely to improve exercise adherence significantly.

Specific properties of shRNA-mediated CCR5 downregulation that enhance the inhibition of HIV-1 infection in combination with shRNA targeting HIV-1 rev.

Treatment with RNAi against HIV-1 transcripts efficiently inhibits viral replication but induces selection of escape mutants; therefore, the CCR5 coreceptor was suggested as an additional target. Blocking viral and host transcripts improved the antiviral effect. We have used short hairpin RNA (shRNA) targeting the human CCR5 (shCCR5) or the HIV-1 rev (shRev) transcripts to demonstrate distinctive properties of anti-CCR5 shRNA: shCCR5 induced more sustained protection than shRev; partial reduction in CCR5 expression substantially decreased HIV-1 infection, and shCCR5 performed better than shRev in the mixed shRNA-treated and untreated cultures. These observations indicate that CCR5 inhibitors should be conveniently included in HIV-1 gene silencing treatment schedules when only a certain cell fraction is protected to further reduce endogenous virus in a properly ART-treated HIV-1 infected individual.

Progression to arthroplasty surgery among patients with hip and knee osteoarthritis : a study from the Swedish BOA Register.

AIMS: The aim of this study was to estimate time to arthroplasty among patients with hip and knee osteoarthritis (OA), and to identify factors at enrolment to first-line intervention that are prognostic for progression to surgery. METHODS: In this longitudinal register-based observational study, we identified 72,069 patients with hip and knee OA in the Better Management of Patients with Osteoarthritis Register (BOA), who were referred for first-line OA intervention, between May 2008 and December 2016. Patients were followed until the first primary arthroplasty surgery before 31 December 2016, stratified into a hip and a knee OA cohort. Data were analyzed with Kaplan-Meier and multivariable-adjusted Cox regression. RESULTS: At five years, Kaplan-Meier estimates showed that 46% (95% confidence interval (CI) 44.6 to 46.9) of those with hip OA, and 20% (95% CI 19.7 to 21.0) of those with knee OA, had progressed to arthroplasty. The strongest prognostic factors were desire for surgery (hazard ratio (HR) hip 3.12 (95% CI 2.95 to 3.31), HR knee 2.72 (95% CI 2.55 to 2.90)), walking difficulties (HR hip 2.20 (95% CI 1.97 to 2.46), HR knee 1.95 (95% CI 1.73 to 2.20)), and frequent pain (HR hip 1.56 (95% CI 1.40 to 1.73), HR knee 1.77 (95% CI 1.58 to 2.00)). In hip OA, the probability of progression to surgery was lower among those with comorbidities (e.g. ≥ four conditions; HR 0.64 (95% CI 0.59 to 0.69)), with no detectable effects in the knee OA cohort. Instead, being overweight or obese increased the probability of OA progress in the knee cohort (HR 1.25 (95% CI 1.15 to 1.37)), but not among those with hip OA. CONCLUSION: Patients with hip OA progressed faster and to a greater extent to arthroplasty than patients with knee OA. Progression was strongly influenced by patients' desire for surgery and by factors related to severity of OA symptoms, but factors not directly related to OA symptoms are also of importance. However, a large proportion of patients with OA do not seem to require surgery within five years, especially among those with knee OA. Cite this article: Bone Joint J 2022;104-B(7):792-800.

Inflammation and Interferon Signatures in Peripheral B-Lymphocytes and Sera of Individuals With Fibromyalgia.

Fibromyalgia (FM) is an idiopathic chronic disease characterized by widespread musculoskeletal pain, hyperalgesia and allodynia, often accompanied by fatigue, cognitive dysfunction and other symptoms. Autoimmunity and neuroinflammatory mechanisms have been suggested to play important roles in the pathophysiology of FM supported by recently identified interferon signatures in affected individuals. However, the contribution of different components in the immune system, such as the B-lymphocytes, in the progression to FM are yet unknown. Furthermore, there is a great need for biomarkers that may improve diagnostics of FM. Herein, we investigated the gene expression profile in peripheral B-cells, as well as a panel of inflammatory serum proteins, in 30 FM patients and 23 healthy matched control individuals. RNA sequence analysis revealed 60 differentially expressed genes when comparing the two groups. The group of FM patients showed increased expression of twenty-five interferon-regulated genes, such as S100A8 and S100A9, VCAM, CD163, SERPINA1, ANXA1, and an increased interferon score. Furthermore, FM was associated with elevated levels of 19 inflammatory serum proteins, such as IL8, AXIN1, SIRT2 and STAMBP, that correlated with the FM severity score. Together, the results shows that FM is associated with an interferon signature in B-cells and increased levels of a set of inflammatory serum proteins. Our findings bring further support for immune activation in the pathogenesis of FM and highlight candidate biomarkers for diagnosis and intervention in the management of FM.

Analgesic prescriptions received by patients before commencing the BOA model of care for osteoarthritis: a Swedish national registry study with matched reference and clinical guideline benchmarking.

Background and purpose - Swedish clinical guidelines for osteoarthritis (OA) prioritize patient education, exercise, and-if necessary-weight reduction before considering adjunct pharmacological intervention. Contrariwise, we investigated the proportion and type of dispensed analgesic prescriptions in Sweden received by patients during 3 years before commencing non-pharmacological primary care interventions for OA (2008-2016) compared with the general population. Furthermore, we analyzed the proportion of analgesic prescriptions dispensed before (2008-2012) compared with after (2012-2016) guideline publication in terms of concordance with clinical guideline recommendations. Patients and methods - Patients with hip or knee OA (n = 72,069) from the Better Management of OA national quality register receiving non-pharmacological interventions in primary care between 2008 and 2016 were included (OA cohort). An age, sex, and residence matched reference cohort (n = 216,207) was formed from the Swedish Total Population Register. Based on a period 3 years prior to inclusion in the OA cohort, Swedish Prescribed Drug Register data was linked to both the OA and reference cohorts. Results - Compared with the reference cohort, a distinctly larger proportion of the OA cohort had dispensed prescriptions for most types of analgesics, increasing exponentially each year prior to commencing non-pharmacological intervention. Since guideline publication, the proportion of the OA cohort having no dispensed prescription analgesics prior to non-pharmacological primary care intervention concordantly increased by 5.0% (95% CI 4.2-5.9). Furthermore, dispensed prescriptions concordantly decreased for non-selective NSAIDs -8.6% (CI -9.6 to -7.6), weak opioids -6.8% (CI -7.7 to -5.9), glucosamine -9.5% (CI -9.8 to -8.8). and hyaluronic acid -1.6% (CI -1.8 to -1.5) but discordantly increased for strong opioids 2.8% (CI 2.1-3.4) and glucocorticoid intra-articular injection for hip OA 2.1% (CI 1.0-3.1). Interpretation - In Sweden, dispensed prescription of analgesics commonly occurred before initiating non-pharmacological primary care interventions for OA but reduced modestly after guideline publication, which prioritizes nonpharmacological before pharmacological interventions. Additional modest improvements occurred in the steppedcare prioritization of analgesic prescription types. However, future strategies are required to curb an increase of strong opioids prescription for OA and glucocorticoid intra-articular injection for hip OA.

Health status of individuals referred to first-line intervention for hip and knee osteoarthritis compared with the general population: an observational register-based study.

OBJECTIVES: To describe the prevalence of comorbidities in a population referred to standardised first-line intervention (patient education and exercise) for hip and knee osteoarthritis (OA), in comparison with the general population. Furthermore, we aimed to evaluate if eventual differences were associated with socioeconomic inequalities. DESIGN: Register-based study. SETTING: Primary healthcare, Sweden. PARTICIPANTS: Individuals with hip and/or knee OA included in the Better Management for Patients with Osteoarthritis Register between 2008 and 2016 and and an age-matched, sex-matched and residence-matched reference cohort (1:3) from the general Swedish population. OUTCOME MEASURES: Comorbidities were identified with the RxRisk Index, the Elixhauser Comorbidity Index and the Charlson Comorbidity Index, and presented with descriptive statistics as (1) individual diseases, (2) disease categories and (3) scores for each index. The prevalence of comorbidities in the two populations was tested using logistic regression, with separate analyses for age groups and the most affected joint. We then adjusted the analyses for socioeconomic status. RESULTS: In this OA population, 85% had ≥1 comorbidity compared with 78% of the reference cohort (OR; 1.62 (95% CI 1.59 to 1.66)). Cardiovascular/blood diseases were the most common comorbidities in both populations (OA, 59%; reference, 54%), with OR; 1.22 (95% CI 1.20 to 1.24) for the OA population. Younger individuals with OA were more comorbid than their matched references overall, and population differences decreased with age (eg, ≥3 comorbidities, aged ≤45 years OR; 1.74 (95% CI 1.52 to 1.98), ≥81 years OR; 0.95 (95% CI 0.87 to 1.04)). Individuals with knee OA were more comorbid than those with hip OA overall. Adjustment for socioeconomic status did not change the estimates. CONCLUSION: Comorbidities were more common among individuals with hip and knee OA than among matched references from the general population. The differences could not be explained by socioeconomic status. TRIAL REGISTRATION NUMBER: NCT03438630.

Socioeconomic status of patients in a Swedish national self-management program for osteoarthritis compared with the general population-a descriptive observational study.

BACKGROUND: First-line treatment for hip and knee osteoarthritis (OA) including education and supervised exercises, delivered as a self-management program, is considered one of the mainstays in OA treatment. However, the socioeconomic profile of the population that utilizes first-line treatment for hip and knee OA is unclear. The aim of this study was to describe the socioeconomic status (SES) of a population referred to a self-management program for OA, in comparison with that of the general Swedish population. METHODS: This is a cross-sectional study including 72,069 patients with hip or knee OA enrolled in the National Quality Register for Better management of patients with Osteoarthritis (BOA) between 2008 and 2016, and registered before participation in a structured OA self-management program. A reference cohort (n = 216,207) was selected from the general Swedish population by one-to-three matching by year of birth, sex and residence. Residential municipality, country of birth, marital status, family type, educational level, employment, occupation, disposable income and sick leave were analyzed. RESULTS: The BOA population had higher educational level than the reference group, both regarding patients with hip OA (77.5% vs 70% with ≥10 years of education), and with knee OA (77% vs 72% with ≥10 years of education). Their average disposable income was higher (median [IQR] in Euro (€), for hip €17,442 [10,478] vs €15,998 [10,659], for knee €17,794 [10,574] vs €16,578 [11,221]). Of those who worked, 46% of patients with hip OA and 45% of the reference group had a blue-collar occupation. The corresponding numbers for knee OA were 51 and 44% respectively. Sick leave was higher among those with hip and knee OA (26%) than those in the reference groups (13% vs 12%). CONCLUSIONS: The consistently higher SES in the BOA population compared with the general population indicates that this self-management program for OA may not reach the more socioeconomically disadvantaged groups, who are often those with a higher disease burden.

Minor influence of patient education and physiotherapy interventions before total hip replacement on patient-reported outcomes: an observational study of 30,756 patients in the Swedish Hip Arthroplasty Register.

Background and purpose - It is unclear whether physiotherapy interventions or patient education before total hip replacement (THR) is beneficial for patients postoperatively. Utilizing the Swedish Hip Arthroplasty Register (SHAR), we retrospectively studied the influence of preoperative self-reported exposure to physiotherapy and/or patient education on patient-reported outcomes 1 year after THR. Patients and methods - Data covering all THRs performed in Sweden for osteoarthritis, between the years 2012 and 2015, was obtained from SHAR. There were 30,756 patients with complete data. Multiple linear regression modelling was performed with 1-year postoperative PROMs (hip pain on a visual analogue scale [VAS], with the quality of life measures EQ-5D index and EQ VAS, and surgery satisfaction VAS) as dependent variables. Self-reported physiotherapy and patient education (yes or no) were used as independent variables. Results - Physiotherapy was associated with slightly less pain VAS (-0.7, 95% CI -1.1 to -0.3), better EQ-5D index (0.01, CI 0.00-0.01), EQ VAS (0.8, CI 0.4-1.2), and better satisfaction VAS (-0.7, CI -1.2 to -0.2). Patient education was associated with slightly better EQ-5D index (0.01, CI 0.00-0.01) and EQ VAS (0.7, CI 0.2-1.1). Interpretation - Even though we found statistically significant differences in favor of physiotherapy and patient education, the magnitude of those were too small and inconsistent to conclude a truly positive influence. Further research is needed with more specific and demarcated physiotherapy interventions.

Study protocol for an observational register-based study on health and risk factors in patients with hip and knee osteoarthritis.

INTRODUCTION: Hip and knee osteoarthritis is a leading cause of disability worldwide. Currently, the course of deterioration in pain and physical functioning in individuals with osteoarthritis is difficult to predict. Factors such as socioeconomic status and comorbidity contribute to progression of osteoarthritis, but clear associations have not been established. There is a need for early identification of individuals with slow disease development and a good prognosis, and those that should be recommended for future joint replacement surgery. METHODS AND ANALYSIS: This nationwide register-based study will use data for approximately 75 000 patients who sought and received core treatment for osteoarthritis in primary healthcare, and were registered in the Swedish population-based National Quality Register for Better Management of Patients with Osteoarthritis. These data will be merged with data for replacement surgery, socioeconomic factors, healthcare consumption and comorbidity from the Swedish Hip Arthroplasty Register, the Swedish Knee Arthroplasty Register, Statistics Sweden and the National Board of Health and Welfare, Sweden. The linkage will be performed using personal identity numbers that are unique to all citizens in Sweden. ETHICS AND DISSEMINATION: The study was approved by the Regional Ethical Review Board in Gothenburg, Sweden (dnr 1059-16). The results from this study will be submitted to peer-reviewed journals and reported at suitable national and international meetings. TRIAL REGISTRATION NUMBER: NCT03438630.

Potentiation of cannabinoid-induced cytotoxicity in mantle cell lymphoma through modulation of ceramide metabolism.

Ceramide levels are elevated in mantle cell lymphoma (MCL) cells following treatment with cannabinoids. Here, we investigated the pathways of ceramide accumulation in the MCL cell line Rec-1 using the stable endocannabinoid analogue R(+)-methanandamide (R-MA). We further interfered with the conversion of ceramide into sphingolipids that promote cell growth. Treatment with R-MA led to increased levels of ceramide species C16, C18, C24, and C(24:1) and transcriptional induction of ceramide synthases (CerS) 3 and 6. The effects were attenuated using SR141716A, which has high affinity to cannabinoid receptor 1 (CB1). The CB1-mediated induction of CerS3 and CerS6 mRNA was confirmed using Win-55,212-2. Simultaneous silencing of CerS3 and CerS6 using small interfering RNA abrogated the R-MA-induced accumulation of C16 and C24. Inhibition of either of the enzymes serine palmitoyl transferase, CerS, and dihydroceramide desaturase within the de novo ceramide pathway reversed ceramide accumulation and cell death induced by R-MA treatment. To enhance the cytotoxic effect R-MA, sphingosine kinase-1 and glucosylceramide synthase, enzymes that convert ceramide to the pro-proliferative sphingolipids sphingosine-1-phospate and glucosylceramide, respectively, were inhibited. Suppression of either enzyme using inhibitors or small interfering RNA potentiated the decreased viability, induction of cell death, and ceramide accumulation induced by R-MA treatment. Our findings suggest that R-MA induces cell death in MCL via CB1-mediated up-regulation of the de novo ceramide synthesis pathway. Furthermore, this is the first study were the cytotoxic effect of a cannabinoid is enhanced by modulation of ceramide metabolism.

Expression of cannabinoid receptors type 1 and type 2 in non-Hodgkin lymphoma: growth inhibition by receptor activation.

Endogenous and synthetic cannabinoids exert antiproliferative and proapoptotic effects in various types of cancer and in mantle cell lymphoma (MCL). In this study, we evaluated the expression of cannabinoid receptors type 1 and type 2 (CB1 and CB2) in non-Hodgkin lymphomas of B cell type (n = 62). A majority of the lymphomas expressed higher mRNA levels of CB1 and/or CB2 as compared to reactive lymphoid tissue. With the exception of MCL, which uniformly overexpresses both CB1 and CB2, the levels of cannabinoid receptors within other lymphoma entities were highly variable, ranging from 0.1 to 224 times the expression in reactive lymph nodes. Low levels of the splice variant CB1a, previously shown to have a different affinity for cannabinoids than CB1, were detected in 44% of the lymphomas, while CB1b expression was not detected. In functional studies using MCL, Burkitt lymphoma (BL), chronic lymphatic leukemia (CLL) and plasma cell leukemia cell lines, the stable anandamide analog R(+)-methanandamide (R(+)-MA) induced cell death only in MCL and CLL cells, which overexpressed both cannabinoid receptors, but not in BL. In vivo treatment with R(+)-MA caused a significant reduction of tumor size and mitotic index in mice xenografted with human MCL. Together, our results suggest that therapies using cannabinoid receptor ligands will have efficiency in reducing tumor burden in malignant lymphoma overexpressing CB1 and CB2.

Cannabinoid receptor-mediated apoptosis induced by R(+)-methanandamide and Win55,212-2 is associated with ceramide accumulation and p38 activation in mantle cell lymphoma.

We have recently shown that cannabinoids induce growth inhibition and apoptosis in mantle cell lymphoma (MCL), a malignant B-cell lymphoma that expresses high levels of cannabinoid receptor types 1 and 2 (CB(1) and CB(2)). In the current study, the role of each receptor and the signal transduction triggered by receptor ligation were investigated. Induction of apoptosis after treatment with the synthetic agonists R(+)-methanandamide [R(+)-MA] and Win55,212-2 (Win55; (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo-[1,2,3-d,e]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone) was dependent on both cannabinoid receptors, because pretreatment with N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR141716A) and N-((1S)-endo-1,3,3-trimethyl bicyclo heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide) (SR144528), specific antagonists to CB(1) and CB(2), respectively, abrogated caspase-3 activity. Preincubation with the inhibitors 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) and 4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)-1H-imidazole (SB202190) showed that phosphorylation of MAPK p38 was implicated in the signal transduction leading to apoptosis. Treatment with R(+)-MA and Win55 was associated with accumulation of ceramide, and pharmacological inhibition of ceramide synthesis de novo prevented both p38 activation and mitochondria depolarization assessed by binding of 3,3'-dihexyloxacarbocyanine iodide (DiOC(6)). In contrast, the pancaspase inhibitor z-Val-Ala-Asp(Ome)-CH(2)F (z-VAD-FMK) did not protect the mitochondrial integrity. Taken together, these results suggest that concurrent ligation of CB(1) and CB(2) with either R(+)-MA or Win55 induces apoptosis via a sequence of events in MCL cells: accumulation of ceramide, phosphorylation of p38, depolarization of the mitochondrial membrane, and caspase activation. Although induction of apoptosis was observed in both MCL cell lines and primary MCL, normal B cells remained unaffected. The present data suggest that targeting CB(1)/CB(2) may have therapeutic potential for the treatment of mantle cell lymphoma.

Cannabinoid receptor ligands mediate growth inhibition and cell death in mantle cell lymphoma.

We have earlier reported overexpression of the central and peripheral cannabinoid receptors CB1 and CB2 in mantle cell lymphoma (MCL), a B cell non-Hodgkin lymphoma. In this study, treatment with cannabinoid receptor ligands caused a decrease in viability of MCL cells, while control cells lacking CB1 were not affected. Interestingly, equipotent doses of the CB1 antagonist SR141716A and the CB1/CB2 agonist anandamide inflicted additive negative effects on viability. Moreover, treatment with the CB1/CB2 agonist Win-55,212-2 caused a decrease in long-term growth of MCL cells in culture. Induction of apoptosis, as measured by FACS/Annexin V-FITC, contributed to the growth suppressive effect of Win-55,212-2. Our data suggest that cannabinoid receptors may be considered as potential therapeutic targets in MCL.