In vitro induction of segregational errors of chromosomes by natural cannabinoids in normal human lymphocytes

Abstract

It has been shown that segregational errors (SE) of chromosomes can be induced by olivetol and several halogenated inhalation anesthetics. The purpose of this study was to examine the effects of natural cannabinoids - including delta-9-tetrahydrocannabinol (THC), cannabinol (CBN), and cannabidiol (CBD) - on chromosome segregation. Lymphocytes obtained from healthy adult males were incubated with various concentrations of natural cannabinoids for 72 hours. Anaphase preparations were made from these cultures. A statistically significant increase in the incidence of SE of chromosomes was observed in the lymphocytes exposed to THC at a concentration of 3.2 x 10(-6) M, but not to CBN or CBD. A greater incidence of bridge formations, anaphase lags, micronuclei, and unequal segregations in bipolar divisions and multipolar divisions were observed in THC-treated lymphocytes, compared with the controls. However, only anaphase lags and unequal segregations in bipolar divisions reached statistically significant levels. It appears that THC affects the formation of microtubules and spindles and may be considered as a mitotic poison. The value of examining SE as a part of cytogenetic studies on chemical mutagens is emphasized. A description of a classification system of SE developed in our laboratory is also presented. This system can be applied to studies using both normal human lymphocyte cultures and lymphoid cell lines.

Epidemiological overview of multidimensional chromosomal and genome toxicity of cannabis exposure in congenital anomalies and cancer development

“…Tubulin polymerization has many key roles in side the cell including the formation of the microtubules of the mitotic spindle and the molecular skeleton of axons, cilia, centrosomes and flagella 106 . Deranged microtubular function has been linked with chromosomes sliding off the mitotic spindle in anaphase and the formation of micronuclei 4 , 6 , 7 , 107 which are described as being a major generator of the genetic chaos of cancer 4 , 107 – 118 . Indeed, just as histones undergo post-translational modifications tubulin has also been shown to undergo post-translational modifications which target the tubulin monomers for different subcellular destinations 105 .…”

“…Cannabinoid-induced genotoxicity was first demonstrated by researchers in the 1960’s who showed multiple congenital defects developing in prenatally exposed animals 1 – 3 , cannabinoid-induced micronucleus formation from chromosomal mis-segregation errors and mitotic spindle disruption 4 , ring and chain chromosomal malformations in sperm 5 , nuclear blebbing and bridging of oocytes and lymphocytes during cytokinesis 6 , 7 and direct and indirect multimodal mitochondrial toxicities with downstream direct and indirect epigenetic effects 4 , 8 – 12 . It has long been known that cannabinoids reduce histone formation and protamine substitution and synthesis resulting in a more open chromosomal conformation which is more subject to mutagenicity and is also pro-oncogenic as more genes are available for transcription 13 – 18 .…”

Cannabinoid exposure as a major driver of pediatric acute lymphoid Leukaemia rates across the USA: combined geospatial, multiple imputation and causal inference study

“…Significant data indicate that interchromosomal translocations or gene amplifications can upregulate oncogenes or downregulate tumour suppressors. The classically documented action of cannabinoids including tetrahydrocannabinol (THC), cannabidiol and cannabinol to induce end-to-end chromosomal fusions, ring chromosomes and chain chromosomes in sperm [ 19 ], and to cause nuclear blebbing and chromosomal bridges between separating nuclei in anaphase and telophase in dividing oocytes and lymphocytes [ 51 – 53 ] constitute in vitro proof of principal that cannabis is at least an indirect chromosomal clastogen as described long ago [ 19 , 54 – 60 ]. Genetic lesions underlying ALL have been proposed by several authors [ 7 , 61 – 64 ].…”

“…The cannabinoids Δ9-THC, Δ8-THC, their hydroxymetabolites, cannabinol, cannabidiol, cannabichromene, cannabicyclol and olivetol which shares the C-ring conformation of these cannabinoids were all shown to impair thymidine, uridine and leucine incorporation into lymphocytic DNA, RNA and protein long ago [ 53 ]. Δ9-THC and olivetol were shown to increase lymphocytic chromosomal segregation errors and the number of hypodiploid cells [ 53 ].…”

“…When normal human lymphocytes from adult volunteers were incubated with micromolar concentrations of Δ9-THC a significant increase in chromosomal segregation errors was observed [ 53 ]. A higher number of chromosomal bridges, anaphase lags, micronuclei, unequal segregations in bipolar divisions and multipolar divisions was noted.…”