RETRACTED: Triptolide inhibits the growth and migration of colon carcinoma cells by down-regulation of miR-191

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Concerns were raised about the background pattern of the Western Blots from Figure 2A. Given the comments of Dr Elisabeth Bik regarding this article “This paper belongs to a set of over 400 papers (as per February 2020) that share very similar Western blots with tadpole-like shaped bands, the same background pattern, and striking similarities in title structures, paper layout, bar graph design, and - in a subset - flow cytometry panels”, the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.

Tanshinone IIA promotes IL2-mediated SW480 colorectal cancer cell apoptosis by triggering INF2-related mitochondrial fission and activating the Mst1-Hippo pathway

IL-2-based therapy is a promising tool to treat colorectal cancer, but drug resistance always occurs in clinical practice. Mitochondrial fission is a novel target to modulate cancer development and progression. The aim of our study is to explore the effect of IL-2 combined with Tan IIA on SW480 colorectal cancer cell apoptosis in vitro and to determine whether IL-2/Tan IIA cotreatment could reduce SW480 cell viability via activating mitochondrial fission. The results indicated that Tan IIA increased IL-2-mediated cell death in SW480 colorectal cancer cells, and this effect was also accompanied with a reduction in cell proliferation. Functional investigations demonstrated that Tan IIA/IL-2 cotreatment enhanced INF2-related mitochondrial fission. Excessive mitochondrial division induced mitochondrial oxidative stress, mitochondrial energy metabolism disorder and mitochondrial apoptosis in SW480 cells. Inhibition of mitochondrial fission attenuated the antitumor effect of Tan IIA/IL-2 cotreatment on SW480 cell apoptosis. Further, we demonstrated that Tan IIA/IL-2 combination therapy controlled INF2-related mitochondrial fission via the Mst1-Hippo pathway. Moreover, Mst1 knockdown abrogated Tan IIA/IL-2-activated mitochondrial fission. Altogether, our results demonstrated that Tan IIA enhances the therapeutic efficiency of IL-2-mediated SW480 colorectal cancer cell apoptosis via promoting INF2-related mitochondrial fission and activating the Mst1-Hippo pathway.

Pentaethylenehexamine and d-penicillamine co-functionalized graphene quantum dots for fluorescent detection of mercury(II) and glutathione and bioimaging

Pentaethylenehexamine and d-penicillamine co-functionalized graphene quantum dots (PEHA-GQD-DPA) was made via one two-step thermal pyrolysis. The resulting PEHA-GQD-DPA is composed of the graphene sheets with an average size of 3.16 nm and the rich of functional groups. It gives an ultra strong fluorescence emission with the fluorescent quantum yield of 90.91% and sensitive and selective optical response towards Hg²⁺. The fluorescence intensity linearly decreases with the increase of Hg²⁺ in the range of 1.0 × 10^-10-2 × 10^-4 M with the detection limit of 4.6 × 10^-11 M (S/N = 3). No species tested interfere with detection of Hg²⁺. The fluorescence quenched by Hg²⁺ can be well recovered by glutathione. The fluorescence intensity linearly increases with the increase of glutathione in the range of 5 × 10^-8-2.5 × 10^-6 M with the detection limit of 1.7 × 10^-8 M (S/N = 3). The PEHA-GQD-DPA as a fluorescence probe has been successfully applied in determination of Hg²⁺ in natural water and glutathione in human serum and SW480 cell imaging.

Chemodiversity of Cirsium fruits: Antiproliferative lignans, neolignans and sesquineolignans as chemotaxonomic markers

While analyzing the fruit composition of nine European Cirsium species representing three sections (i.e., Cephalonoplos, Chamaeleon and Eriolepis), four lignans, three neolignans and three sesquineolignans were determined and used as chemotaxonomic markers. Among them, desmethyl balanophonin and desmethyl picrasmalignan were determined for the first time in the plant kingdom, as the main metabolites of the Chamaeleon section. Prebalanophonin and prepicrasmalignan, identified so far exclusively in C. eriophorum, were also confirmed in C. boujartii and C. vulgare, highlighting the chemotaxonomic significance of these compounds in the Eriolepis section. The antiproliferative assay of the compounds isolated from their optimum sources, confirmed a dose-dependent inhibitory effect of the structures bearing the 4',7-epoxy moiety (balanophonin, picrasmalignan, desmethyl balanophonin, desmethyl picrasmalignan) against SW480 colon cancer cells, while those bearing the 4',7-dihydroxy motif (prebalanophonin, prepicrasmalignan) were inactive.

Transfection of methylated oligonucleotides inactivates the CHFR gene in human colon cancer cell line SW480

AIM: To investigate whether transfection of methylated oligonucleotides that are complementary to the CHFR (checkpoint with forkhead and ring finger domains) gene promoter inactivates the CHFR gene in human colon cancer cell line SW480 and to analyze the effect of CHFR inactivation on the biological behavior of SW480 cells.

METHODS: After methylated oligonucleotides that are complementary to the CHFR gene promoter were transfected into SW480 cells, MSP and RT-PCR were employed to detect the promoter methylation status and mRNA expression of the CHFR gene, respectively. MTT assay was used to detect the proliferation of SW480 cells before and after transfection.

RESULTS: In control SW480 cells, the promoter region of the CHFR gene was unmethylated and CHFR mRNA expression could be detected. After transfection of methylated oligonucleotides, CHFR gene promoter methylation was induced and CHFR mRNA expression was suppressed. The proliferation of SW480 cells transfected with methylated oligonucleotides was significantly higher than that of control cells.

CONCLUSION: Methylated oligonucleotides that are complementary to the CHFR gene promoter can induce CHFR gene promoter methylation, suppress CHFR mRNA expression, and promote cell proliferation in human colon cancer cell line SW480.

Relationship between intracellular Ca2+ and ALA-PDT induced apoptosis in SW480 cells

AIM: To investigate relationship between intracellular Ca²⁺ and apoptosis induced by aminolaevulinic acid-photodynamic therapy (ALA-PDT) in SW480 cells.

METHODS: SW480 cells were divided into control, light, ALA and ALA-PDT group. The corresponding treatment was performed in each group. The apoptosis of SW480 cells was detected by DNA fragment assay and TUNEL assay. The changes of intracelluar Ca²⁺ concentration in each group were observed by confocal laser scanning microscopy.

RESULTS: DNA ladder formation of apoptotic features was demonstrated 1 and 2 h after ALA-PDT treatment. The apoptosis index (AI) of 30 and 60 min after ALA-PDT treatment was 25.26% ± 5.04% and 50.45% ± 7.85%, respectively, which were significantly higher than those in the other 3 groups (all AI <10%, P < 0.01). The concentration of intracelluar Ca²⁺ 20 min after ALA-PDT treatment was markedly increased than that at 10 min (fluorescent intensity: 185.40 ± 18.90 vs 100.00 ± 19.83, P < 0.01), and then gradually decreased. However, the concentrations of intracelluar Ca²⁺ had no significant changes in the other 3 groups.

CONCLUSION: The increases of intracellular Ca²⁺ may play an important role in the ALA-PDT-induced apoptosis in SW480 cells.