Izidalwa Zokuhlukunyezwa Kwezingcingo - Umsebenzi, Ukungahleleki, Nendima Ekhanda
Yiziphi izakhi zofuzo ezihlukumezayo? Zihluke kanjani lezi zinhla ze-oncogenes, futhi zithini indima ekuthuthukiseni umdlavuza nomdlavuza wefa?
Incazelo: Izitshalo zokucindezeleka ezihlukumezayo
Izakhi zofuzo zokudambisa i-tumor yizakhi zofuzo ezilawula ukukhula kwamaseli. Lapho lezi zakhi zofuzo zisebenza ngendlela efanele, zingavimbela futhi zivimbele ukukhula kwezidumbu.
Lapho izifo zofuzo ezicindezelayo ziguqulwa noma zingasebenzi (ngenxa yomsindo), zilahlekelwa amandla okwenza amaprotheni alawula ukukhula kweseli.
Amaseli angase akhule angalawulwa futhi ahlakulele abe ngumdlavuza.
Izinhlobo ze-Gumorous Suppressor Genes
Kunezinhlobo ezintathu eziyinhloko zezinkinga zokuphefumula zesisu.
- Uhlobo olulodwa lutshela amangqamuzana ukuthi anciphise futhi ayeke ukuhlukanisa.
- Olunye uhlobo lubangela ukulungisa umonakalo ku-DNA engenzeka uma amaseli ehlukana (i-DNA yokulungisa izakhi zofuzo.)
- Uhlobo lwesithathu lunomthwalo wokutshela amangqamuzana ukuthi afe, inqubo ebizwa ngokuthi i-apoptosis noma i-cell cell death.
I-Analogy Yokushayela - Izidakamizwa Zokucindezela Ukuhlukunyezwa yi-Brakes
Ngayo yonke izindaba mayelana ne-immunotherapy , nezinzwa zokuzwa kanye nezicucu mayelana "kokuvula nokuvala" umdlavuza, kungasiza, ngokulula kakhulu, ucabange ngamaseli njengemoto. Esitokisini ngasinye, kune-accelerator nama-brake. Ezimoto ezivamile, zombili zisebenza kahle. Izinqubo eziningi ziqinisekisa ukuthi zihlala zilinganiselwe ngakho imoto ihamba njalo njalo, kodwa ayiqhubi.
I-Cancer iqala ngochungechunge lwezinguquko. Ezinye izinguquko aziyona into enkulu-sibheka kubo njengokuguqulwa komgibeli.
Amaphutha amaphutha yilokho okubandakanya umshayeli. Umshayeli anganquma ukuhamba ngokushesha noma kancane. Ungase uzwe ngalokhu ngokuthi "ukuguqulwa komshayeli" hhayi ngenxa yokuthi baqhuba imoto, kodwa ngoba baqhuba ukukhula kwamangqamuzana omdlavuza.
I-Cancer ingaxhunyaniswa nezinkinga ezihambisana ne-accelerator noma ama-brakes, kodwa ngokuvamile, ukulimala kwamagciwane okulawula kokubili kwalokhu kuyadingeka ukudala umdlavuza.
Ukuthi umdlavuza udinga ukuguqulwa okwehlukahluka kwesinye esinye sezizathu zokuthi kungani umdlavuza uvame kakhulu kubantu asebekhulile.
I-oncogenes , ngokufana, izakhi zofuzo ezilawula i-accelerator. Igama elithi oncogenes lisho ngokoqobo "umdlavuza wegciwane."
Ama-genes wokucindezela ama-tumor , ngokungafani ne-oncogenes, yi-brakes. Izakhi zofuzo ezidambisa isisu zifana nesakhiwo. Bafaka ikhodi yamaphrotheni abese enesibopho sokuphuma nokushaya amabhuleki.
Isikhathi esiningi sokuba iseli ukuba nomdlavuza, sidinga ukushintshashintsha kokubili kwe-oncogenes kanye nezakhi zofuzo zokuphefumula. Ngamanye amazwi, i-accelerator kufanele ibambelele phansi futhi ama-brakes kufanele asebenze kabi.
I-Oncogenes vs I-Tumor Suppressor Genes
Kukhona umehluko obalulekile phakathi kwama-oncogenes kanye nezakhi zofuzo zokuphefumula kwe-tumor emdlalweni. Ngokuvamile, i-oncogenes inamandla . Emizimbeni yethu, sinamaqoqo amabili e-chromosomes ngayinye namasethi amabili wezakhi zofuzo - esisodwa kubazali bethu ngamunye. Ngokuvamile uma isakhi sofuzo esisodwa singasebenzi kahle, enye ingakwazi ukukhokhela. Kungenzeka ukuthi wezwe ngefa. Uma uzwile ngefa lombala wamehlo, umehluko phakathi kwama-oncogenes amaningi kanye nama-geni wokucindezela i-tumor kulula ukuwaqonda. Ama-oncogenes athambekele ekubuseni-njengamahlo aluhlaza.
Uma enye yezinhlobo zomzimba ingase ishukumise i-accelerator kanzima kakhulu, ingabangela umdlavuza. Izakhi zofuzo ezihlukumezayo, ngokuphambene nalokho, zivame ukushintsha ngokweqile . Lokhu kungukuthi, njengoba nje udinga izakhi zomzimba ezihlaza okwesibhakabhaka ukuze ube nezingane eziluhlaza okwesibhakabhaka, ama-gciwane amabili okucindezelayo kufanele awonakele kabili ukuze abe nengxenye yomdlavuza.
Izidakamizwa zokudambisa izidumbu kanye nefa elibusayo - "2 Hit Hypothesis"
Ukuqonda ukukhubazeka kwezifo zofuzo eziphefumulayo kungasiza ekuqondeni izifo ezithathelwanayo ezifweni.
Isibonelo yisifo se-tumor suppressor amagciwane BRCA1 / BRCA2 - okunye okubizwa ngokuthi "izakhi zomdlavuza webele." Abantu abanezakhi zomzimba kulezi zakhi zofuzo banomngcipheko owengeziwe wokuthuthukisa umdlavuza webele (phakathi kwabanye.) Kodwa akubona wonke umuntu onesisindo odala umdlavuza webele.
Lapho isakhi sesibili esingasetshenziswanga sishintsha, ukuguqulwa okutholakele, okusho ukuguquguquka kwesinye somzimba okwenzeka ngemva kokuzalwa, umdlavuza ungaholela.
Imvelo eguquguqukayo yikho okukhulunywa ngayo uma uzwa "2 hit hypothesis" yomdlavuza. Ezinye ze-khansa ziqala (okungenani ekupheleni kokucindezeleka kwesisu, kodwa khumbula ukuthi kubuye kube nokuguquguquka kwe-oncogene) ngemuva kokuguqulwa kwe-2 ku-genetic suppressor gene. Ukuguqulwa kokuqala kungenzeka kube khona kusukela ekuzalweni, okubizwa ngokuthi "i-germ mutation." Okwesibili, "ukuguquguquka kwe-somatic" kutholakala futhi kuhlobene nento ethile emvelweni ngemuva kokuzalwa.
Umlando
Izakhi zofuzo zokudambisa izidakamizwa zaqala ukubonakala phakathi kwezingane ezine-retinoblastoma. Ku-retinoblastoma, ngokuphambene, i-genetic suppressor gene ezuzwe njengefa iyinhloko-ngakho-ke ivumela umdlavuza ukuba uthuthuke ezinganeni ezincane.
Izidakamizwa zokudambisa izidumbu
Kube sekukhona izinambuzane eziningana zokucindezela izifo ezikhonjiwe. Ezinye zazo zihlanganisa:
- I-RB - I-genetic suppressor ephethe i-retinoblastoma
- i-p53 gene - I- p53 gene gene code for protein p53 . Izinguquko kule geythini zibandakanya cishe ezingamaphesenti angu-50 zamanqamu.
- B RCA1 / BRCA2 - Lezi zakhi zofuzo zinomthwalo wamaphesenti angaba ngu-5 kuya kumaphesenti angu-10 emdlavuza webele. (I- BRCA2 ixhunyaniswe nengozi yomdlavuza wamapayipi yamaphaphu kwabesifazane .)
- Igayela le-APC - Lezi zakhi zofuzo zihlotshaniswa nobungozi obuningi bomdlavuza wekoloni kubantu abanezinhlobo ze-polyposis ezithandwayo.
Okwenza Ukwelashwa Kwemitholampilo Akusebenzi Njalo
Ukuqonda izakhi zofuzo zomzimba we-tumor kungasiza ekuchazeni ukuthi kungani ukwelashwa, njenge-chemotherapy, kungakhambi kahle umdlavuza. Ezinye zokwelashwa komdlavuza zisebenza ukukhuthaza amangqamuzana ukuba azibulale. Njengoba ezinye izifo zofuzo ezicindezelayo zithinteka ekusebenzeni kwe-apoptosis (ukufa kwe-cell) amangqamuzana omdlavuza angeke ahambe ngenqubo ye-apoptosis njengoba amanye amangqamuzana angase abe.
Okuningi mayelana nomdlavuza
Ukufunda ngegciwane lokucindezela isisu kuyingxenye eyodwa yokuqonda ukuthuthukiswa nokusinda komdlavuza. Funda ngokuqondile ukuthi iyini isifo somdlavuza , nokuthi amangqamuzana omdlavuza ahluke kanjani kumangqamuzana avamile .
Futhi ebizwa ngokuthi : i- antioncogene, ukulahlekelwa kwemisebenzi yezakhi zofuzo
Izibonelo: Amansela amaningi amaphaphu anomuthi angavamile we-p53 ngaphakathi kwesisu. i-p53 iyisisindo sokucindezela isisu esithintekayo ukuqinisekisa ukuthi amaseli afa uma i-DNA yabo ibonakalisiwe futhi ayikwazi ukulungiswa (apoptosis).
> Imithombo:
> I-American Cancer Society. I-Oncogenes ne-Tumor Suppressor Genes. Kubuyekezwe 06/25/14. http://www.cancer.org/cancer/cancercauses/geneticsandcancer/genesandcancer/genes-and-cancer-oncogenes-tumor-suppressor-genes