Oncogene ndi jini yam'manja yomwe mawu ake amatha kulimbikitsa kukula kwa khansa. Kodi mitundu yosiyanasiyana ya oncogene ndi iti? Kodi amayatsidwa ndi makina otani? Mafotokozedwe.

Oncogene (kuchokera ku Greek onkos, chotupa ndi genos, kubadwa) amatchedwanso proto-oncogene (c-onc) ndi jini yomwe mawu ake amatha kupereka khansa pa selo yachibadwa ya eukaryotic. Zowonadi, ma oncogene amayang'anira kaphatikizidwe ka mapuloteni omwe amathandizira kugawanika kwa maselo (otchedwa oncoproteins) kapena amalepheretsa kufa kwa cell (kapena apoptosis). Oncogenes ali ndi udindo pakuchulukirachulukira kwa ma cell mosalamulirika komwe kumatsogolera kukula kwa maselo a khansa.

Ma oncogene amagawidwa m'magulu 6 omwe amafanana motsatana ndi ma oncoprotein omwe amawasunga:

• kukula zinthu. Chitsanzo: mapuloteni a proto-oncogene encoding a banja la FGF (Fibroblast Growth Factor);
• Transmembrane kukula factor receptors. Chitsanzo: proto-oncogene erb B yomwe imayimira cholandilira cha EGF (Epidermal Growth Factor);
• Mapuloteni a G kapena mapuloteni a membrane omwe amamanga GTP. Chitsanzo: ma proto-oncogene a m’banja la ras;
• nembanemba tyrosine mapuloteni kinases;
• membrane protein kinases;
• mapuloteni okhala ndi nyukiliya.Chitsanzo: ma proto-oncogenes erb A, phos, June et c-myc.

Kukonzanso kwa ma cell kumatsimikiziridwa ndi kayendedwe ka selo. Chotsatiracho chimatanthauzidwa ndi zochitika zomwe zimapanga maselo awiri aakazi kuchokera ku selo la mayi. Tikukamba za kugawanika kwa ma cell kapena "mitosis".

Kuzungulira kwa ma cell kuyenera kuyendetsedwa. Zoonadi, ngati kugawanika kwa maselo sikukwanira, chamoyocho sichigwira ntchito bwino; Mosiyana ndi zimenezi, ngati kugawanika kwa maselo kuli kochuluka, maselo amachulukana mosalamulirika, zomwe zimalimbikitsa maonekedwe a maselo a khansa.

Kuwongolera kwa kayendedwe ka maselo kumatsimikiziridwa ndi majini ogawidwa m'magulu awiri:

• anti-oncogenes omwe amalepheretsa kuchuluka kwa maselo pochepetsa kufalikira kwa maselo;
• ma proto-oncogenes (c-onc) kapena ma oncogenes omwe amalimbikitsa kuchulukana kwa maselo poyambitsa kuzungulira kwa ma cell.

Tikayerekeza kuzungulira kwa selo ndi galimoto, ma anti-oncogenes angakhale mabuleki ndipo ma proto-oncogenes angakhale ma accelerators otsiriza.

Maonekedwe Chotupacho chingabwere chifukwa cha kusintha koyambitsa ma anti-oncogenes kapena m'malo mwake chifukwa choyambitsa ma proto-oncogenes (kapena oncogenes).

Kutayika kwa ntchito ya anti-oncogenes kumawalepheretsa kuchita ntchito yoletsa kufalikira kwa maselo. Kuletsa kwa anti-oncogenes ndi khomo lotseguka la kugawanika kwa maselo kosalamulirika komwe kungayambitse maonekedwe a maselo oipa.

Komabe, ma anti-oncogenes ndi ma gene a cell, ndiye kuti, amapezeka mowirikiza pama chromosome omwe amawanyamula mu phata la selo. Choncho, pamene kopi imodzi ya anti-oncogene sikugwira ntchito, ina imapangitsa kuti ikhale yonyezimira kuti mutuwo utetezedwe ku kuchuluka kwa maselo komanso kuopsa kwa zotupa. Izi ndizochitika, mwachitsanzo, za jini ya BRCA1, kusintha koletsa komwe kumawonetsa khansa ya m'mawere. Koma ngati kopi yachiwiri ya jiniyi ikugwira ntchito, wodwalayo amakhalabe otetezedwa ngakhale kuti ali ndi chiyembekezo chifukwa cha cholakwika choyamba. Monga gawo lachidziwitso chotere, njira yopewera mastectomy nthawi zina imaganiziridwa.

Kumbali ina, kusintha koyambitsako komwe kumakhudza ma proto-oncogenes kumawonjezera chidwi chawo pakuchulukitsa kwa maselo. Kuchulukana kwa maselo amtunduwu kumapangitsa kuti khansa iyambe.

Monga ma anti-oncogenes, ma pro-oncogene ndi majini am'manja, omwe amapezeka mobwerezabwereza pama chromosome omwe amanyamula. Komabe, mosiyana ndi anti-oncongens, kukhalapo kwa pro-oncogene imodzi yosinthika ndikokwanira kutulutsa zotsatira zowopsya (pankhani iyi, kuchuluka kwa maselo). Choncho, wodwalayo ali pachiwopsezo chotenga khansa.

Kusintha kwa ma oncogene kumatha kukhala modzidzimutsa, cholowa kapena chifukwa cha ma mutagens (mankhwala, kuwala kwa UV, etc.).

Njira zingapo zili poyambira kuyambitsa masinthidwe a oncogene kapena pro-oncogenes (c-onc):

• kuphatikiza kwa ma virus: kuyika kwa kachilombo ka DNA pamlingo wa jini yowongolera. Izi ndi mwachitsanzo nkhani ya human papillomavirus (HPV), yomwe imafalikira pogonana;
• kusintha kwa jini motsatizana ndi jini yoyika puloteni;
• deletion: kutayika kwa kachidutswa kakang'ono ka DNA, komwe kumayambitsa kusintha kwa chibadwa;
• kukonzanso kamangidwe: kusintha kwa chromosomal (translocation, inversion) kumapangitsa kupanga jini yosakanizidwa yomwe imasunga mapuloteni osagwira ntchito;
• kukulitsa: kuchulutsa kwachilendo kwa chiwerengero cha makope a jini muselo. Kukulitsa uku kumabweretsa kuwonjezeka kwa mawonekedwe a jini;
• kuchotsedwa kwa mawu a RNA: majini amachotsedwa ku malo omwe amakhalapo ndipo amaikidwa pansi pa ulamuliro wosayenera wa ndondomeko zina zomwe zimapangitsa kusintha kwa maonekedwe awo.

Ma gene omwe amasunga zinthu zakukulira kapena zolandilira zawo:

• PDGF: imayika gawo la kukula kwa mapulateleti okhudzana ndi glioma (khansa ya muubongo);
  Erb-B: imayika epidermal growth factor receptor. Glioblastoma (khansa ya ubongo) ndi khansa ya m'mawere;
• Erb-B2 imatchedwanso HER-2 kapena neu: imayika cholandirira chakukula. Zogwirizana ndi khansa ya m'mawere, salivary gland ndi ovarian;
• RET: imakhazikitsa kukula kwa chinthu cholandirira. Zogwirizana ndi khansa ya chithokomiro.

Ma gene omwe amasunga ma cytoplasmic relay munjira zokondoweza:

• Ki-ras: yokhudzana ndi khansa ya m'mapapo, yamchiberekero, m'matumbo ndi kapamba;
• N-ras: yokhudzana ndi khansa ya m'magazi.

Zinthu zolembera za majini zomwe zimathandizira jini zomwe zimalimbikitsa kukula:

• C-myc: yokhudzana ndi khansa ya m'magazi ndi khansa ya m'mawere, m'mimba ndi m'mapapo;
• N-myc: yokhudzana ndi neuroblastoma (khansa ya mitsempha ya mitsempha) ndi glioblastoma;
• L-myc: yokhudzana ndi khansa ya m'mapapo.

Majini akuyika mamolekyu ena:

• Hcl-2: imayika puloteni yomwe nthawi zambiri imaletsa kudzipha kwa ma cell. Kugwirizana ndi ma lymphoma a B lymphocytes;
• Bel-1: amatchedwanso PRAD1. Encodes Cyclin DXNUMX, choyambitsa mawotchi ozungulira ma cell. Zogwirizana ndi khansa ya m'mawere, mutu ndi khosi;
• MDM2: imayika wotsutsana ndi mapuloteni opangidwa ndi chotupa chopondereza jini.
• P53: yolumikizidwa ndi ma sarcoma (makhansa olumikizira minofu) ndi makhansa ena.

Ma virus a oncogenic ndi ma virus omwe amatha kupanga cell yomwe amapatsira kukhala khansa. 15% ya makhansa ali ndi etiology ya ma virus ndipo ma virus awa ndi omwe amayambitsa pafupifupi 1.5 miliyoni miliyoni pachaka ndi kufa 900 pachaka padziko lonse lapansi.

Makhansa okhudzana ndi ma virus ndi vuto laumoyo wa anthu:

• papillomavirus kugwirizana ndi pafupifupi 90% ya khomo lachiberekero khansa;
• 75% ya hepatocarcinomas imalumikizidwa ndi kachilombo ka hepatitis B ndi C.

Pali magulu asanu a ma virus a oncogenic, kaya ndi ma virus a RNA kapena ma virus a DNA.

RNA ma virus

• Retroviridae (HTVL-1) imakuikani pachiopsezo cha T leukemia;
• Flaviviridae (kachilombo ka hepatitis C) ali pachiwopsezo cha hepatocellular carcinoma.

Ma virus a DNA

• Papovaviridae (papillomavirus 16 ndi 18) imayambitsa khansa ya pachibelekero;
• Herpesviridae (Esptein Barr virus) imayambitsa B lymphoma ndi carcinoma;
• Herpesviridae (herpesvirus 8) imayambitsa matenda a Kaposi ndi lymphomas;
• Hepadnaviridae (kachilombo ka hepatitis B) amatha kutenga kachilombo ka hepatocellular carcinoma.