Attenuation of chloroquine and hydroxychloroquine on the invasive potential of bladder cancer through targeting matrix metalloproteinase 2 expression

Hydroxychloroquine had neutral effect on long-term risk of malignancy in rheumatoid arthritis patients: A population-based retrospective cohort study

BACKGROUND

The cancer risk in rheumatoid arthritis (RA) patients has been discussed. Hydroxychloroquine (HCQ) may exert protective effects against malignancy. The study investigated the association between HCQ use and the risk of subsequent malignancy in RA patients.

METHODS

Catastrophic illness certificated RA patients were extracted from the National Health Insurance Research Database. The index date was set 180 days after the RA diagnosis date to avoid immortal time bias. Two groups were matched in a 1-to-1 ratio by propensity score regarding age, gender, index date, relevant comorbidities, and comedication. HCQ users prior to the diagnosis of RA were exempted to ensure compliance with the new-user design. Cancers diagnosed before or less than 180 days after the index date were excluded to mitigate protopathic bias. The study adopted the Kaplan-Meier curve and Cox proportional hazards model to examine the association between HCQ use and cancer risk. The assumption of proportional hazard was also tested.

RESULTS

Based on strict criteria, we included 492 eligible RA patients and divided them into study and control groups (N = 246 in each group). HCQ users exhibited a neutral risk of cancer relative to the controls (adjusted hazard ratio, 0.99; 95% CI, 0.44-2.21, p > .05). The assumption of proportional hazard was not violated.

CONCLUSION

This study does not observe the effect of using HCQ as a primary regimen to prevent cancer in RA patients. We are assured that HCQ is not associated with an increased risk of subsequent malignancy in RA patients. Further mechanistic research is needed.

Autophagy blockade potentiates cancer-associated immunosuppression through programmed death ligand-1 upregulation in bladder cancer

A high basal level of autophagic flux in bladder cancer (BC) cells prevents cell death and weakens chemotherapy efficacy. However, how autophagy influences cancer-associated immunosuppression in BC remains undetermined. In this study, we observed a negative correlation between the autophagy-related markers LC3-II and programmed death ligand-1 (PD-L1) in BC cells. The autophagy inhibitors chloroquine (CQ) and bafilomycin A1 (Baf-A1) increased PD-L1 expression in BC cells through the ERK-JNK-c-Jun signal-transduction pathway. Moreover, the treatment of BC cells with CQ and Baf-A1 inhibited hsa-microRNA-34a (miR-34a) expression and miR-34a overexpression in BC cells prevented the autophagy blockade-induced PD-L1 expression; a negative correlation between miR-34a and PD-L1 expression was observed during treatment with autophagy inhibitors. Furthermore, miR-34a overexpression induced the cytotoxic activity of natural killer cells against BC cells. Our results provide evidence that autophagy blockade and its regulatory pathway affect cancer-associated immunosuppression through PD-L1 elevation. Thus, the coadministration of autophagy inhibitors and a PD-L1 immune checkpoint blockade provides a potential therapeutic approach for treating BC.

Hydroxychloroquine attenuates neuroinflammation following traumatic brain injury by regulating the TLR4/NF-κB signaling pathway

Background

After traumatic brain injury (TBI), an acute, robust inflammatory cascade occurs that is characterized by the activation of resident cells such as microglia, the migration and recruitment of peripheral immune cells and the release of inflammatory mediators that induce secondary cell death and impede neurological recovery. In addition, neuroinflammation can alter blood–brain barrier (BBB) permeability. Controlling inflammatory responses is considered a promising therapeutic approach for TBI. Hydroxychloroquine (HCQ) has already been used clinically for decades, and it is still widely used to treat various autoimmune diseases. However, the effects of HCQ on inflammation and the potential mechanism after TBI remain to be defined. The aim of the current study was to elucidate whether HCQ could improve the neurological recovery of mice post-TBI by inhibiting the inflammatory response via the TLR4/NF-κB signaling pathway.

Methods

C57BL/6 mice were subjected to controlled cortical impact (CCI) and randomly divided into groups that received intraperitoneal HCQ or vehicle daily after TBI. TAK-242 (3.0 mg/kg), an exogenous TLR4 antagonist, was injected intraperitoneally 1 h before TBI. Behavioral assessments were performed on days 1 and 3 post-TBI, and the gene expression levels of inflammatory cytokines were analyzed by qRT-PCR. The presence of infiltrated immune cells was examined by flow cytometry and immunostaining. In addition, BBB permeability, tight junction expression and brain edema were investigated.

Results

HCQ administration significantly ameliorated TBI-induced neurological deficits. HCQ alleviated neuroinflammation, the activation and accumulation of microglia and immune cell infiltration in the brain, attenuated BBB disruption and brain edema, and upregulated tight junction expression. Combined administration of HCQ and TAK-242 did not enhance the neuroprotective effects of HCQ.

Conclusions

HCQ reduced proinflammatory cytokine expression, and the underlying mechanism may involve suppressing the TLR4/NF-κB signaling pathway, suggesting that HCQ is a potential therapeutic agent for TBI treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02430-0.