The Effects Of Morphine On Growth And Proliferation Of Tumor And The Investigation Of Molecular Mechanisms

Part1The effects of morphine on the growth of humanbreast cancer MCF-7cellsObjective：To observe the effects of morphine on the growth andproliferation of human breast cancer MCF-7cells and explore thepossible mechanisms.Methods：Human human breast cancer cells MCF-7were seeded in6-well or96-well plates and divided into7groups:0.01μmol/L morphinegroup(group M1),0.1μmol/L morphine group(group M2),1μmol/Lmorphine group(group M3),0.1mmol/L morphine group(group M4),0.01mmol/L naloxon group(group N),(0.1mmol/L morphine+0.01mmol/L naloxon) group(group MN) and control group(group C). MCF-7cells were cultured to logarithmic phase. The cells in morphine groupswere incubated with0.01μmol/L、0.1μmol/L、1μmol/L、0.1mmol/Lmorphine respectively while group N was incubated with0.01mmol/Lnaloxon and group MN was incubated with0.01mmol/L naloxon for30 min and then0.1mmol/L morphine was added to the culture medium.The cells in control group were incubated normally. The viability of cellswas determined by MTT assay and the proliferation of cells wasdetermined by colony formation assay. The cell cycle progression andapoptosis were assessed by flow cytometry.Results： The proliferation of MCF-7cells was inhibited afterexposed to0.01μmol/L、0.1μmol/L、1μmol/L、0.1mmol/L morphinemorphine or0.1mmol/L morphine+0.01mmol/L naloxon respectively(P<0.05). Clones of breast cancer cells MCF-7in morphine groups andgroup MN were fewer than those in control group (P<0.05). In morphinegroups and group MN, the proportion of cells in G2/M was higher thanthat in group C (P<0.05). Compared with cells in group C, the apoptoticrates were higher in morphine groups and group MN (P<0.05).Conclusions：Morphine can induce apoptosis and inhibit growth andproliferation of breast cancer cells MCF-7in vitro. Part2The effects of morphine on the growth of humangastric carcinoma cell line MGC-803cellsObjective：To observe the effects of morphine on the growth andproliferation of human gastric carcinoma cell line MGC-803and explorethe possible mechanisms.Methods：Human gastric carcinoma MGC-803cells were seeded in6-well or96-well plates and and divided into7groups:0.01μmol/L morphine group(group M1),0.1μmol/L morphine group(group M2),1μmol/L morphine group(group M3),0.1mmol/L morphine group(groupM4),0.01mmol/L naloxon group(group N),(0.1mmol/L morphine+0.01mmol/L naloxon) group(group MN) and control group(group C).MGC-803cells were cultured to logarithmic phase. The cells in morphinegroups were incubated with0.01μmol/L、0.1μmol/L、1μmol/L、0.1mmol/L morphine respectively while group N was incubated with0.01mmol/L naloxon and group MN was incubated with0.01mmol/Lnaloxon for30min and then0.1mmol/L morphine was added to theculture medium. The cells in control group were incubated normally. Theviability of cells was determined by MTT assay and the proliferation ofcells was determined by colony formation assay. The cell cycleprogression and apoptosis were assessed by flow cytometry.Results：The proliferation of MGC-803cells was inhibited afterexposed to was inhibited after exposed to0.01μmol/L、0.1μmol/L、1μmol/L、0.1mmol/L morphine morphine respectively. Clones of gastriccarcinoma cell line MGC-803in morphine groups were fewer than thosein group C(P<0.05). In morphine groups, the proportion of cells in G2/Mwas higher than that in group C(P<0.05). Compared with cells in group C,the apoptotic rates were higher in morphine groups (P<0.05). Moreover,naloxon could antagonize the anti-cancer effects of morphine.Conclusions：Morphine can induce apoptosis and inhibit growth andproliferation of gastric cancer MGC-803cells in vitro. Part3The effects of morphine on subcutaneous tumor of humangastric cancer MGC-803cell in nude miceObjective: To observe the effects of morphine on subcutaneoustumor of human gastric cancer MGC-803cell in nude mice.Method: The model of subcutaneous tumor of human gastric cancerMGC-803cell in nude mice were established.40nude mice randomlydivided into8groups: control group(group C), normal saline group(1.5ml/kg NS), group M1(5mg/kg morphine), group M2(10mg/kgmorphine), group M3(20mg/kg morphine), and group M4(40mg/kgmorphine), group N (1mg/kg naloxone), group MN(20mg/kg morphine+1mg/kg naloxone), there were5mices in each group. After the tumordiameter reached to1.0cm×1.0cm in length and width, group Creceived no treatment, while group NS, group M1, group M2, group M3,group M4, group N and group MN were injected with1.5ml/kg saline,5mg/kg morphine,10mg/kg morphine,20mg/kg morphine,40mg/kgmorphine,1mg/kg naloxone,20mg/kg morphine+1mg/kg naloxonerespectively perday. The solutions for all the groups were injectedintraperitoneal. The volumes of tumors in nude mouse subcutaneous wereobserved. Transmission electron microscope observe morphologicalchanges of tumor tissue; The expression of NF-κB、Bcl-2、Bax、VEGF、MMP-9mRNA and proteins were detected by semi-quantitative reversetranscription polymerase chain reaction(RT-PCR), immunochemistrystaining and Western blot.Result: RTV in morphine groups were significantly less than that ingroup C (P＜0.05); we observed apoptotic bodies in morphine groups;the expression of NF-κB、Cyclin d1、Bcl-2、VEGF、MMP-9were upregulated while the expression of Bax were downregulated in morphinegroups. Naloxon could antagonize the anti-growth effects of morphine.Conclusion:Morphine could inhibit the growth of subcutaneoustumor of human gastric cancer MGC-803cell in nude mice possibly bydownregulating the expression of NF-κB, Cyclin d1, Bcl-2, VEGF andMMP-9while upregulating the expression of Bax through theconbindaiton of μ recepter.