Nature雜志：2023年，超過1萬篇SCI高級論文撤搞。

網(wǎng)址：https://pubmed.ncbi.nlm./38087103/

中國作者撤稿占到所有SCI論文撤稿的49.86%！

中國撤稿率23.5%。

無言！

很多人在做RNA干擾的時候，都會遇到一個奇葩的問題：通過慢病毒轉(zhuǎn)染shRNA，基因敲低了，然而傳代幾次之后，或者把之前凍存的穩(wěn)轉(zhuǎn)細(xì)胞株復(fù)蘇后，再次檢測，發(fā)現(xiàn)原本敲低的蛋白質(zhì)水平，又回到從前，為什么？

終于查到一篇這方面的正式的文獻(xiàn)（并非來自論壇留言區(qū)了）。

Li W, Shen M, Jiang YZ, et al. Deubiquitinase USP20 promotes breast cancer metastasis by stabilizing SNAI2. Genes Dev. 2020;34(19-20):1310-1315. doi:10.1101/gad.339804.120

全文：

https://genesdev./content/34/19-20/1310.full.pdf+html

USP20 knockdown inhibits lung colonization by breast cancer cells

USP20敲低抑制乳腺癌細(xì)胞肺轉(zhuǎn)移

Given the important role of SNAI2 in metastasis, we next investigated the effect of USP20 on lung metastasis of breast cancer cells.

鑒于SNAI2基因在轉(zhuǎn)移中的重要作用，我們接下來研究了USP20基因?qū)θ橄侔┘?xì)胞肺轉(zhuǎn)移的影響。

First, we generated cell lines with stable USP20 knockdown using lentiviruses containing USP20-targeting shRNAs.The protein level of SNAI2 was decreased when the cell lines were first generated.

首先，我們使用含有靶向USP20 shRNAs的慢病毒構(gòu)建了具有穩(wěn)定USP20敲低的細(xì)胞系。當(dāng)細(xì)胞系首次構(gòu)建時，SNAI2的蛋白質(zhì)水平降低。

However, the SNAI2 protein level in USP20 knockdown cells recovered after several passages, possibly because SNAI2 is essential for LM2 cells and the cells developed compensating mechanisms to regain SNAI2 expression over time.

然而，USP20敲除細(xì)胞株中的SNAI2蛋白水平在幾次傳代后恢復(fù)，這可能是因為SNAI2對LM2細(xì)胞（人高轉(zhuǎn)移性乳腺癌細(xì)胞系）至關(guān)重要，并且隨著時間的推移，細(xì)胞出現(xiàn)了補(bǔ)償機(jī)制來恢復(fù)SNAI2的表達(dá)。

Thus, we took an alternative approach of knocking down USP20 using two different siRNAs, and the siRNA knockdown effect was confirmed to last for at least 10 d, which is sufficient for in vivo experimental lung colonization studies (Supplemental Fig. S3A,B).

因此，我們采用了另一種方法，即使用兩種不同的siRNA敲除USP20，并證實siRNA敲除效果持續(xù)至少10天，這足以進(jìn)行體內(nèi)實驗性肺轉(zhuǎn)移研究（補(bǔ)充圖S3A、B）。

Firefly luciferase-labeled siRNA transfected SUM159-M1a and LM2 cells were injected intravenously into NSG mice, and bioluminescent imaging (BLI) was used to monitor their metastatic seeding and growth in the lung.

將螢火蟲熒光素酶標(biāo)記siRNA轉(zhuǎn)染的SUM159-M1a和LM2細(xì)胞通過靜脈注射到NSG小鼠體內(nèi)，并使用生物發(fā)光成像（BLI）監(jiān)測其在肺部的轉(zhuǎn)移接種和生長。

Five days after injection, there was already a significantly lower number of cancer cells seeded in the lung for USP20 or SNAI2 knockdown cells compared with the control cells (Fig. 4A; Supplemental Fig. S4A).

注射后五天，與對照細(xì)胞相比，在肺中接種USP20或SNAI2敲低細(xì)胞的癌癥細(xì)胞數(shù)量已經(jīng)顯著減少（圖4A；補(bǔ)充圖S4A）。

This effect was maintained for at least 3 wk for both siRNAs of USP20 after injection of LM2 cells, and then the two siRNAs of USP20 diverged at week 4, possibly due to different knockdown efficiencies in vivo (Fig. 4B).

注射LM2細(xì)胞后，USP20的兩種siRNA的這種效果至少持續(xù)了3周，然后USP20的這兩種siRNA在第4周出現(xiàn)分化，這可能是由于體內(nèi)敲除效率不同造成的（圖4B）。

Mice were sacrificed 4 wk later and metastasis nodules on the lungs were counted. Significantly less lung metastasis nodules were observed for USP20 and SNAI2 knockdown groups (Fig. 4C,D), which could result from both reduced lung seeding as well as a modest decrease in proliferation (Supplemental Fig. S4B).

4周后處死小鼠，計數(shù)肺部轉(zhuǎn)移結(jié)節(jié)。USP20和SNAI2敲除組的肺轉(zhuǎn)移結(jié)節(jié)明顯減少（圖4C，D），這可能是由于肺接種減少和增殖適度減少造成的（補(bǔ)充圖S4B）。

這個WB，666666。

海星生物的一篇文章：做shRNA干擾細(xì)胞系，細(xì)胞系傳代次數(shù)不能過多，大量客戶反饋表明，shRNA干擾穩(wěn)轉(zhuǎn)細(xì)胞系在傳代超過10次之后，干擾水平會顯著降低，可能因為：細(xì)胞的代謝補(bǔ)償、導(dǎo)入序列被甲基化修飾。