Minocycline for symptom reduction during radiation therapy for head and neck cancer: a randomized clinical trial

Minocycline as a prospective therapeutic agent for cancer and non-cancer diseases: a scoping review

Minocycline is an FDA-approved secondary-generation tetracycline antibiotic. It is a synthetic antibiotic having many biological effects, such as antioxidant, anti-inflammatory, anti-cancer, and neuroprotective functions. This study discusses the pharmacological mechanisms of preventive and therapeutic effects of minocycline. Specifically, it provides a comprehensive overview of the molecular pathways by which minocycline acts on the different cancers, including ovarian, breast, glioma, colorectal, liver, pancreatic, lung, prostate, melanoma, head and neck, leukemia, and non-cancer diseases such as Alzheimer's disease, Parkinson, schizophrenia, multiple sclerosis, Huntington, polycystic ovary syndrome, and coronavirus disease 19. Minocycline may be a potential medication for these disorders due to its strong blood-brain barrier penetrance. It is also widely accepted as a specific medication, has a well-known side-effect characteristic, is reasonably priced, making it appropriate for continuous use in managing diseases, and has been demonstrated as an oral approach because it is effectively absorbed and accomplished almost all of the body's parts.

Minocycline declines interleukin-1ß-induced apoptosis and matrix metalloproteinase expression in C28/I2 chondrocyte cells: an in vitro study on osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that occurs with aging. In its late phases, it is determined by the loss of chondrocytes and the breakdown of the extracellular matrix, resulting in pain and functional impairment. Interleukin-1 beta (IL-1β) is increased in the injured joints and contributes to the OA pathobiology by inducing chondrocyte apoptosis and up-regulation of matrix metalloproteinases (MMPs). Here, we aimed to understand whether minocycline could protect chondrocytes against the IL-1β-induced effects. The human C28/I2 chondrocyte cell line was treated with IL-1β or IL-1β plus minocycline. Cell viability/toxicity, cell cycle progression, and apoptosis were assessed with MMT assay and flow cytometry. Expression of apoptotic genes and MMPs were evaluated with qRT-PCR and western blotting. IL-1β showed a significant cytotoxic effect on the C28/I2 chondrocyte cells. The minocycline effective concentration (EC50) significantly protected the C28/I2 cells against the IL-1β-induced cytotoxic effect. Besides, minocycline effectively lowered IL-1β-induced sub-G1 cell population increase, indicating the minocycline anti-apoptotic effect. When assessed by real-time PCR and western blotting, the minocycline treatment group showed an elevated level of Bcl-2 and a significant decrease in the mRNA and protein expression of the apoptotic markers Bax and Caspase-3 and Matrix metalloproteinases (MMPs) such as MMP-3 and MMP-13. In conclusion, IL-1β promotes OA by inducing chondrocyte death and MMPs overexpression. Treatment with minocycline reduces these effects and decreases the production of apoptotic factors as well as the MMP-3 and MMP-13. Minocycline might be considered as an anti-IL-1β therapeutic supplement in the treatment of osteoarthritis. See also the graphical abstract(Fig. 1).

Tetracycline antibiotics: Potential anticancer drugs

In recent years, research on tetracycline antibiotics has gradually shifted from their antibacterial effects to anticancer effects. Doxycycline, minocycline, and tigecycline as the US Food and Drug Administration (FDA) approved tetracycline antibiotics have been the main subjects of studies. Evidence indicated that they have anticancer properties and are able to control cancer progression through different mechanisms, such as anti-proliferation, anti-metastasis, and promotion of autophagy or apoptosis. In addition, studies have shown that these three tetracycline antibiotics can be utilized in conjunction with chemotherapeutic and targeted drugs to inhibit cancer progression and improve the quality of patient survival. Therefore, doxycycline, minocycline, and tigecycline are taken as examples in this work. Their mechanisms of action in different cancers and related combination therapies are introduced. Their current roles in alleviating the suffering of patients undergoing chemotherapy when used as adjuvant drugs in clinical treatment are also described. Finally, the research gaps and potential research directions at this stage are briefly summarized.

Minocycline Protects PC12 Cells Against Cadmium-Induced Neurotoxicity by Modulating Apoptosis

Cadmium (Cd) is a well-known heavy metal and a neurotoxic agent. Minocycline (Mino) is an anti-microbial agent with a lipophilic structure that crosses the blood-brain barrier and enters the cerebral tissue. In recent studies, Mino has been introduced as an antioxidant and anti-apoptotic chemical compound, and therefore, it was examined as a protective candidate against Cd-induced neurotoxicity. In this study, PC12 cells were exposed to Cd alone, or after being pre-treated with Mino. Initially, the cell viability and oxidative stress were analyzed using the MTT assay and fluorimetry, respectively. Then, Cd-induced apoptosis and Mino anti-apoptotic effect were evaluated in both intrinsic and extrinsic pathways using western blot analysis. Exposing PC12 cells to Cd for 24 h decreased cell viability and increased production of reactive oxygen species in comparison with the control group. Cd (35 μM) also elevated the level of caspase-8, Bax/Bcl-2, and caspase-3 proteins in the cells. Mino pre-treatment for 2 h (100 nM) increased the number of viable cells and decreased the production of reactive oxygen species, and the level of all apoptotic markers in comparison to Cd-treated cells. Considering all the evidence, it appears that Mino holds promising antioxidant and anti-apoptotic activity and can protect cells against Cd-induced oxidative stress and prevent apoptotic cell death.

The protective effect of natural or chemical compounds against arsenic-induced neurotoxicity: Cellular and molecular mechanisms

Arsenic is a notorious metalloid that exists in the earth's crust and is considered toxic for humans and the environment. Both cancerous and non-cancerous complications are possible after arsenic exposure. Target organs include the liver, lungs, kidney, heart, and brain. Arsenic-induced neurotoxicity, the main focus of our study, can occur in central and peripheral nervous systems. Symptoms can develop in a few hours, weeks, or years depending on the quantity of arsenic and the duration of exposure. In this review, we aimed to gather all the compounds, natural and chemical, that have been studied as protective agents in cellular, animal, and human reports. Oxidative stress, apoptosis, and inflammation are frequently described as destructive mechanisms in heavy metal toxicity. Moreover, reduced activity of acetylcholinesterase, the altered release of monoamine neurotransmitters, down-regulation of N-methyl-D-aspartate receptors, and decreased brain-derived neurotrophic factor are important underlying mechanisms of arsenic-induced neurotoxicity. As for neuroprotection, though some compounds have yet limited data, there are others, such as curcumin, resveratrol, taurine, or melatonin which have been studied more deeply and might be closer to a reliable protective agent. We collected the available information on all protective agents and the mechanisms by which they fight against arsenic-induced neurotoxicity.

A Drug Screening Reveals Minocycline Hydrochloride as a Therapeutic Option to Prevent Breast Cancer Cells Extravasation across the Blood-Brain Barrier

Among breast cancer (BC) patients, 15-25% develop BC brain metastases (BCBM), a severe condition due to the limited therapeutic options, which points to the need for preventive strategies. We aimed to find a drug able to boost blood-brain barrier (BBB) properties and prevent BC cells (BCCs) extravasation, among PI3K, HSP90, and EGFR inhibitors and approved drugs. We used BCCs (4T1) and BBB endothelial cells (b.End5) to identify molecules with toxicity to 4T1 cells and safe for b.End5 cells. Moreover, we used those cells in mixed cultures to perform a high-throughput microscopy screening of drugs' ability to ameliorate BBB properties and prevent BCCs adhesion and migration across the endothelium, as well as to analyse miRNAs expression and release profiles. KW-2478, buparlisib, and minocycline hydrochloride (MH) promoted maximal expression of the junctional protein β-catenin and induced 4T1 cells nucleus changes. Buparlisib and MH further decreased 4T1 adhesion. MH was the most promising in preventing 4T1 migration and BBB disruption, tumour and endothelial cytoskeleton-associated proteins modifications, and miRNA deregulation. Our data revealed MH's ability to improve BBB properties, while compromising BCCs viability and interaction with BBB endothelial cells, besides restoring miRNAs' homeostasis, paving the way for MH repurposing for BCBM prevention.

Salivary Gland Hypofunction and/or Xerostomia Induced by Nonsurgical Cancer Therapies: ISOO/MASCC/ASCO Guideline

PURPOSE

To provide evidence-based recommendations for prevention and management of salivary gland hypofunction and xerostomia induced by nonsurgical cancer therapies.

METHODS

Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) and ASCO convened a multidisciplinary Expert Panel to evaluate the evidence and formulate recommendations. PubMed, EMBASE, and Cochrane Library were searched for randomized controlled trials published between January 2009 and June 2020. The guideline also incorporated two previous systematic reviews conducted by MASCC/ISOO, which included studies published from 1990 through 2008.

RESULTS

A total of 58 publications were identified: 46 addressed preventive interventions and 12 addressed therapeutic interventions. A majority of the evidence focused on the setting of radiation therapy for head and neck cancer. For the prevention of salivary gland hypofunction and/or xerostomia in patients with head and neck cancer, there is high-quality evidence for tissue-sparing radiation modalities. Evidence is weaker or insufficient for other interventions. For the management of salivary gland hypofunction and/or xerostomia, intermediate-quality evidence supports the use of topical mucosal lubricants, saliva substitutes, and agents that stimulate the salivary reflex.

RECOMMENDATIONS

For patients who receive radiation therapy for head and neck cancer, tissue-sparing radiation modalities should be used when possible to reduce the risk of salivary gland hypofunction and xerostomia. Other risk-reducing interventions that may be offered during radiation therapy for head and neck cancer include bethanechol and acupuncture. For patients who develop salivary gland hypofunction and/or xerostomia, interventions include topical mucosal lubricants, saliva substitutes, and sugar-free lozenges or chewing gum. For patients with head and neck cancer, oral pilocarpine and oral cevimeline, acupuncture, or transcutaneous electrostimulation may be offered after radiation therapy.Additional information can be found at www.asco.org/supportive-care-guidelines.

Minocycline for symptom reduction in patients with multiple myeloma during maintenance therapy: a phase II placebo-controlled randomized trial

BACKGROUND

Patients with multiple myeloma (MM) experience substantial cancer/treatment-related symptom burden during maintenance therapy. This is a phase II randomized, double-blinded, placebo-controlled clinical trial to examine the effect of minocycline for symptom reduction by its potential anti-inflammatory effect.

METHODS

Eligible MM patients for maintenance therapy were randomized to receive minocycline (100 mg twice daily) or placebo. The MD Anderson Symptom Inventory for MM (MDASI-MM) was used to assess multiple symptoms weekly during the trial. Clinician-rated toxicities and blood samples were prospectively collected. The effect size, area under the curve (AUC), and t tests were used to determine the symptom burden between treatment groups and identify the 5 most-severe MDASI-MM symptoms. The longitudinal analysis compared the changes in symptom severity and associated inflammatory markers between groups over time.

RESULTS

Sixty-nine evaluable MM patients (33 from the intervention group and 36 from the placebo group) were included. No grade 3+ adverse events related to study medication were noted. The AUCs for the 5 worst MDASI-MM symptoms (fatigue, pain, disturbed sleep numbness/tingling, and drowsiness) were not significantly different between two arms. Regardless of group assignment, pain reduction was positively associated with decreased serum levels of soluble tumor necrosis factor-α receptors 1 and 2 during therapy (all P < 0.05).

CONCLUSIONS

This pPhase II randomized study observed no statistically significant positive signal impact from minocycline on symptom reduction or inflammatory markers during maintenance therapy for MM, although using minocycline was feasible and had a low toxicity profile.

A Randomized, Placebo-Controlled, Double-Blind Study of Minocycline for Reducing the Symptom Burden Experienced by Patients With Advanced Pancreatic Cancer

CONTEXT

Although it is well known that patients with advanced pancreatic cancer (PC) experience significant symptom burden, few strategies for effective symptom intervention are available for them.

OBJECTIVES

To investigate the efficacy of minocycline, an anti-inflammatory agent, for symptom reduction in patients with advanced PC.

METHODS

We conducted Phase II, randomized, and placebo-controlled trial to obtain preliminary estimates of the effects on symptom reduction with 100 mg of minocycline or placebo given twice a day. Eligible patients had diagnosed advanced PC and were scheduled for standard chemotherapy. Patient-reported symptoms were measured weekly during the eight-week trial using the MD Anderson Symptom Inventory (MDASI) module in patients with gastrointestinal cancer. The primary outcome measure was the area under the curve values of the five most severe symptoms in the two arms.

RESULTS

Of the 44 patients recruited, 31 (71%) were evaluable for the primary efficacy analysis, with 18 received minocycline and 13 placebo. Fatigue, pain, disturbed sleep, lack of appetite, and drowsiness were the most severe symptoms reported by both groups. No significant differences in area under the curve values over time between the study arms were found for the composite MDASI score or single-item scores of the five most severe MDASI items. No treatment-related deaths were reported, and no Grade 3-4 toxicities were observed.

CONCLUSION

Minocycline is safe for use in patients receiving treatment for PC. There is no observed symptom reduction with minocycline on the major symptom burden associated with advanced PC compared with placebo. Attrition because of rapid disease progression impacted the study significantly.

Minocycline, focus on mechanisms of resistance, antibacterial activity, and clinical effectiveness: Back to the future

OBJECTIVES

The increasing crisis regarding multidrug-resistant (MDR) and extensively drug-resistant microorganisms leads to appealing therapeutic options.

METHODS

During the last 30 years, minocycline, a wide-spectrum antimicrobial agent, has been effective against MDR Gram-positive and Gram-negative bacterial infections. As with other tetracyclines, the mechanism of action of minocycline involves attaching to the bacterial 30S ribosomal subunit and preventing protein synthesis.

RESULTS

This antimicrobial agent has been approved for the treatment of acne vulgaris, some sexually transmitted diseases and rheumatoid arthritis. Although many reports have been published, there remains limited information regarding the prevalence, mechanism of resistance and clinical effectiveness of minocycline.

CONCLUSION

Thus, we summarize here the currently available data concerning pharmacokinetics and pharmacodynamics, mechanism of action and resistance, antibacterial activity and clinical effectiveness of minocycline.

Minocycline Reduces Chemoradiation-Related Symptom Burden in Patients with Non-Small Cell Lung Cancer: A Phase 2 Randomized Trial

PURPOSE

In patients with non-small cell lung cancer (NSCLC), concurrent chemoradiation therapy (CRT) exacerbates a cluster of difficult-to-manage symptoms, especially cancer-related fatigue. Minocycline is a readily available, low-cost antibiotic with antiinflammatory properties. We conducted a phase 2 randomized, double-blinded, placebo-controlled trial to investigate the effect of minocycline in reducing CRT-symptom burden in NSCLC.

METHODS AND MATERIALS

Patients with NSCLC scheduled to receive CRT provided consent and were randomized to receive either minocycline (100 mg twice daily) or a matching placebo during 6 to 7 weeks of CRT. Patient-reported fatigue and other symptoms were assessed on MD Anderson Symptom Inventory weekly from the start of CRT for 12 weeks. The primary outcome was 12-week (±2 days) area under the curve for symptom burden, which was compared between treatment groups.

RESULTS

Forty of 49 enrolled patients (80%) were evaluable (19 on minocycline and 21 on placebo). There were no grade 3 + adverse events related to the study medication. Fatigue was significantly reduced in the minocycline group compared with placebo group during the 12-week trial period (area under the curve = 31.2 ± 14.2 vs 45.0 ± 20.9, P = .011), with a large effect size (Cohen's d = 0.77). Pain (Cohen's d = 0.54) and shortness of breath (Cohen's d = 0.55) were also significantly reduced in the minocycline group (all P < .05).

CONCLUSIONS

Minocycline during CRT for NSCLC was feasible, had a low toxicity profile, and yielded a clinically and statistically significant positive signal in reducing symptom burden related to NSCLC and CRT. This study is a proof of concept so a larger trial in CRT patients is warranted.