Research Article

Insights into the Roles of Midazolam in Cancer Therapy

Table 1

Characteristics of included studies.

First authorYearAreaStudy designCell lines/animalConcentrations of midazolamPathwayAssaysResultsConclusion

Stevens [12]2011NetherlandsIn vitroHuman lymphoma and neuroblastoma cell lines0, 50, 70, 100, and 150 μM for Jurkat T-lymphoma cells
0, 100, 200, 300, and 400 μM
neuroblastoma cells
Mitochondrial pathwayXTT assayMidazolam induced apoptosis in all investigated cell types in a concentration-dependent manner. Bcl2 overexpression and caspase-9 deficiency protected against toxicity, whereas caspase-8 or FADD deficiency had no effect.Midazolam induces apoptosis via activation of the mitochondrial pathway in a concentration-dependent manner. The mechanism of midazolam toxicity switches from caspase-dependent apoptosis to necrosis with increasing concentrations of midazolam.

Mak [28]1997Hong KongIn vitroMurine myeloid leukemia WEHI 3B (JCS) and M1 cells0, 10, 20, 30, and 40 μg/ml for both JCS and M1 cells for 18, 48, and 72 hoursNAFlow cytometry;
mRNA phenotyping; phagocytosis;
cell morphology;
Southern-blot
Midazolam inhibits proliferation of both M1 and JCS cells in a dose-dependent manner. mRNA phenotyping also indicated that the expression of tumor necrosis factor and the neutrophil-specific J11d differentiation marker was significantly upregulated in midazolam-treated JCS cells. In addition, the phagocytic activity of midazolam-treated JCS cells was increased towards opsonized yeast cells.Midazolam inhibits proliferation of both M1 and JCS cells.

So [29]2014TaiwanIn vitroMA-10 mouse Leydig tumor cell line0, 6, 30, and 150 μM for 3, 6, 12, and 24 hourspAkt pathway and p38 and c-Jun NH2-terminal
kinase pathways
Flow cytometry and
immunoblotting analysis
Midazolam induced the accumulation of the MA-10 cell population in the sub-G1 phase and a reduction in the G2/M phase, in a time- and dose-dependent manner. It induced the activation of caspase-8, caspase-9, and caspase-3 and poly(ADP-ribose) polymerase, decreased both pAkt and Akt expression, and stimulated the phosphorylation of p38 and c-Jun NH2-terminal kinase.Midazolam induced MA-10 cell apoptosis via activation of the caspase cascade, the inhibition of pAkt pathway, and the induction of p38 and c-Jun NH2-terminal kinase pathways.

Ohno [30]2012JapanIn vitroHuman OSCC cell lines;
HL-60 cells;
glioblastoma;
keratinocytes;
oral normal cells
0–1000 μM for 3, 6, 9, 12, 24, and 48 hoursNACytotoxic activity by MTT;
DNA fragmentation by ultraviolet irradiation;
caspase activation;
autophagy;
electron microscopy
Midazolam showed the highest cytotoxicity. In HL-60 cells, it induced the appearance of many vacuoles, mitochondrial swelling, and cell membrane rupture in HSC-2 and HSC-4 cells.Midazolam may induce necrotic cell death, rather than apoptosis or autophagy, in OSCC cell lines.

So [31]2016TaiwanIn vitroMA-10 mouse Leydig tumor cells 0, 6, 30, and 150 μM for 1, 3, 6, 12, and 24 hoursER stress and
p53 pathway
Flow cytometry assay and Western blot analysesMidazolam significantly decreased cell viability but increased sub-G1 phase cell numbers and apoptosis. Expression of Fas, Fas ligand, p-EIF2α, ATF4, ATF3, CHOP, and LC3-II proteins was detected. Midazolam was able to regulate the cell cycle via regulation of the p53 pathway.Midazolam induced cell apoptosis in MA-10 mouse Leydig tumor cells through activation of ER stress and regulation of the cell cycle via the p53 pathway, with the involvement of autophagy.

Braun [32]2015GermanyIn vitroHuman neuroblastoma cells2, 4, 8, 16, 128, 256, and 512 μM for 24 and 48 hoursNACell proliferation; cell cycle; cell viabilityMidazolam increased cell viability at lower concentrations, whereas higher concentrations reduced cell viability.Midazolam causes a hormetic dose-response relationship in human neuroblastoma cells.

Dou [33]2014ChinaIn vitroHypopharyngeal squamous carcinoma cells 0, 6.25, 12.5, 25, 50, and 100 μM for 24 and 48 hoursCDKI/RB pathwayMTT and BrdU incorporation
RT-PCR and Western blotting
Midazolam inhibited the expression of p300 and the proliferation of FaDu cells. Additionally, knockdown of p300 resulted in increased expression of p21 and p27 and decreased expression of p-Rb, while inhibiting the proliferation of FaDu cells.Midazolam inhibits the proliferation of human head and neck squamous carcinoma cells by downregulating p300.

Dou [34]2013ChinaIn vitroFaDu human hypopharyngeal squamous cell carcinoma cells 0, 6.25, 12.5, 25, 50, and 100 μM for 24 and 48 hoursTRPM7 inhibitionCell death assay;
cell cycle analysis;
Western blot analysis;
quantitative real-time PCR
Midazolam inhibits the growth and proliferation of FaDu cells. Midazolam triggers G0/G1 cell cycle arrest by regulating cell cycle regulators. The inhibitory effect of midazolam on proliferation is benzodiazepine receptor- (BR-) independent but TRPM7-dependent.The inhibitory activity of midazolam on cancer cell growth and proliferation, combined with the TRPM-dependent mechanism, reveals the anticancer potential of midazolam as a TRPM7 inhibitor.

Mishra [35]2013KoreaIn vitro;
in vivo
BALB/c-nu mice bearing K562 and HT29 cells human tumor xenografts0, 10, 30, 100, and 200 μM for 24 and 48 hours (in vitro),
0.83 mg/kg body weight (in vivo)
Mitochondrial intrinsic pathwayCell viability;
flow cytometric analysis;
cell cycle analysis;
measurement of mitochondrial membrane potential;
DNA fragmentation;
Western blot;
intracellular superoxide generation;
in vivo mouse xenograft
Midazolam decreased the viability of K562 and HT29 cells by inducing apoptosis and S phase cell-cycle arrest in a concentration-dependent manner. Midazolam activated caspase-9, caspase-3 and PARP, lowered mitochondrial membrane potential, increased apoptotic DNA fragmentation, and exhibited ROS scavenging activity through the inhibition of NADPH oxidase 2 (Nox2) enzyme activity in K562 cells. It also resulted in inhibition of pERK1/2 signaling which led to inhibition of the antiapoptotic proteins Bcl-XL and XIAP and phosphorylation activation of the proapoptotic protein Bid. Midazolam inhibited growth of HT29 tumors in xenograft mice.Midazolam inhibited the growth of cancer cells via activation of the mitochondrial intrinsic pathway of apoptosis. It also inhibited HT29 tumor growth in xenograft mice. The mechanism underlying these effects may be suppression of ROS production leading to modulation of apoptosis and growth regulatory proteins.

Chen [36]2016ChinaIn vitroMalignant glioblastoma cell line T98-MG cells0, 25, 50, and 100 μM for 24 and 48 hoursInhibited the TRPM7 expressionImmunofluorescence;
cell proliferation and cell viability;
caspase-3 activity and LDH release assay;
reverse transcription-PCR;
electrophysiology;
cell cycle analysis;
Western blot analysis;
calcium imaging
Brief midazolam treatment (seconds) suppressed TRPM7 channels and calcium influx, while treatment for 48 h inhibited the TRPM7 expression. The inhibitory effect on TRPM7 accounts for the decrease in proliferation and G0/G1 phase cell cycle arrest induced by midazolam.Midazolam represses proliferation of human malignant glioma cells via the inhibition of TRPM7 channels.

Hong [37]2013ChinaIn vitroMantle cell; lymphoma JeKo-1 cell line10, 20, 40, and 80 μmol/L for 24, 48, 72 hoursMitochondrial pathwayCCK8;
flow cytometry;
Western blot
Midazolam inhibited the growth of JeKo-1 cells; it induced apoptosis and reduction of Bcl-2, procaspase-9, and procaspase-3 protein expression and an increase in cyto-C protein expression in a concentration-dependent manner.Midazolam may initiate the mitochondrial pathway by reducing the expression of Bcl-2, leading in turn to the release of Cyto-C in the mitochondria. This leads to the activation of caspase-9 and caspase-3 protein and triggers the caspase cascade, ultimately inducing apoptosis of the JeKo-1 cells.

Dou [38]2012ChinaIn vitroHuman colon cancer SW480 cells0, 6.25, 12.5, 25, 50, and 100 μM for 24 and 48 hoursCDKI/Rb pathwayMTT and BrdU incorporation
RT-PCR and Western blotting
Midazolam inhibited the growth and proliferation of SW480 cells in a time- and dose-dependent manner. It downregulated USP22 expression. When USP22 expression was silenced by siRNA, proliferation of the SW480 cells was inhibited. P21 and P27 expression was upregulated, while pRB was downregulated.Midazolam inhibits the proliferation of human colon cancer SW480 cells. The mechanism may be through mediation of the CDKI/RB pathway via downregulation of USP22.

GABAA, γ-aminobutyric acid A; CBM, Chinese Biomedical Literature; Bci-2, B cell lymphoma 2; FADD, Fas-associating protein with a novel death domain; ER stress, endoplasmic reticulum stress; CHOP, C/EBP-homologous protein; ATF-4, activating transcription factor 4; p-eIF2α, phosphorylated α subunit of eukaryotic initiation factor 2; Bax, Bcl-2 associated X; OSCC, oral squamous cell carcinoma; LC3-II, LC3-phosphatidylethanolamine conjugate; CKD1, cyclin-dependent kinase 1; TRPM7, transient receptor potential melastatin 7; USP22, ubiquitin-specific protease 22; CDKI/RB, cyclin-dependent kinase inhibitor/retinoblastoma protein; TNF, tumor necrosis factor; ROS, reactive oxygen species; NA: not applicable.