c-Met Targeting Enhances the Effect of Irradiation and Chemical Agents against Malignant Colon Cells Harboring a <i>KRAS</i> Mutation

<div><p>Although EGFR-targeted therapy has been beneficial to colorectal cancer patients, several studies have showed this clinical benefit was restricted to patients with wild-type <i>KRAS</i> exon 2 colorectal cancer. Therefore, it is crucial to explore efficient treatment strategies in patients with <i>KRAS</i> mutations. c-Met is an emerging target for the development of therapeutics against colorectal cancer. In this study, we first used the SW620 cell line, which has an activating <i>KRAS</i> mutation, to generate a stable cell line with conditional regulation of c-Met, which is an essential gene for growth and an oncogene. Using this approach, we evaluated the benefits of combined c-Met-targeted therapy with irradiation or chemical agents. In this cell line, we observed that the proliferation and migration of SW620 cells were reduced by the induction of c-Met shRNA. Furthermore, c-Met knockdown enhanced the anti-proliferative effects of 5-FU and Taxol but not cisplatin, irinotecan or sorafenib. These enhancements were also observed in another colon cancer cells line HCT-116, which also has a <i>KRAS</i> mutation. The response of SW620 cells to irradiation was also enhanced by c-Met knockdown. This method and obtained data might have important implications for exploring the combinatory effects of targeted therapies with conventional medications. Moreover, the data suggested that the combination of c-Met-targeted therapy with chemotherapy or irradiation might be an effective strategy against colorectal cancer harboring a <i>KRAS</i> mutation.</p></div

Strategic Construction of <i>meso</i>-Aryl-Substituted <i>N,N</i>-Carbonyl-Bridged Dipyrrinones as Small, Bright, and Tunable Fluorophores

A series of novel N,N-carbonyl-bridged dipyrrinone fluorophores have been directly constructed from α-halogenated dipyrrinones, which are conveniently obtained from the acid-catalyzed hydrolysis of readily available α,α′-dihalodipyrrins. This novel methodology affords efficient modulation of the functional groups at both the meso- and α-positions of this fluorophore. These resultant dyes show tunable absorption and emission wavelengths, good molar absorption coefficients, relatively large Stokes shifts, and excellent fluorescence quantum yields up to 0.99, and have been successfully applied in both one- and two-photon fluorescence microscopy imaging in living cells

The effects of c-Met conditional knockdown on cell proliferation and migration.

<p>(A) Effect of c-Met knockdown on cell proliferation. SW620, SW620-Scr and SW620-shRNA cells were treated with or without DOX (400 nM) for 72 h. The cells were then seeded in 96-well plates and cultivated for 1–5 days. Cell proliferation was determined using an Alamar Blue assay. The values are expressed as the mean ± SD. (B) and (C) Effect of c-Met knockdown on cell migration. SW620, SW620-Scr and SW620-shRNA cells were treated with DOX (400 nM) for 72 h. Cell migration was then determined using a transwell migration assay. (B) Representative results of the migration assay. (C) The number of migrating cells was expressed as a percentage of SW620 cells without DOX treatment. The data are shown as the mean ± SD. **P<0.01.</p

Effects of c-Met knockdown on the antitumor activity of 5-FU chemotherapy in nude mice bearing human colon cancer SW620 xenografts.

<p>(A) and (B) Antitumor efficacy in the SW620 model with 5-FU, PHA-665752 (PHA), or 5-FU plus PHA-665752 (5-FU + PHA) treatments. (A) Representative image of the SW620 model. (B) Tumor weight changes in the SW620 model. The data are shown as the mean ± SD (n = 8). (C) and (D) Ki67-positive staining and statistics for cells per field of view from paraffin-embedded sections of SW620 tumors treated with 5-FU, PHA or 5-FU plus PHA. Scale bar  = 20 µm. (E) and (F) TUNEL-positive staining and statistics for cells per field of view from paraffin-embedded sections of SW620 tumors treated with 5-FU, PHA or 5-FU plus PHA. Scale bar  = 20 µm. *P<0.05 and **P<0.01.</p

c-Met levels are regulated by DOX in c-Met conditional knockdown SW620 cells.

<p>Cells transduced with pSD400 containing scrambled shRNA (Scr) or c-Met-shRNA (shRNA) were treated with DOX for 72 h, and the cells were processed for (A) Western blot analysis, (B) real-time PCR analysis and (C) immunofluorescence staining. The data shown are representative of three independent experiments with similar results.</p

c-Met siRNA transient and stable transfection.

<p>(A) Sequences of c-Met-siRNAs and scramble siRNA. (B) and (C) c-Met-siRNAs were transiently transfected into SW620 cells, and the efficiency of c-Met knockdown was determined by (B) Western blot and (C) real-time PCR analyses. (D) SW620 cells were transiently transfected with c-Met-siRNA3. The cell viability was determined with an Alamar blue assay 24 or 48 h post-transfection. (E) The c-Met expression in SW620 (Ctrl), scramble-siRNA (Scr) or c-Met-siRNA3 (S3) stable knockdown cells was analyzed by a Western blot assay. c-Met expression returned to normal levels after the continuous cultivation of c-Met-siRNA3 stable knockdown cells. *P<0.05 and ***P<0.001.</p

Additional file 2 of Comprehensive analysis of the differences between left- and right-side colorectal cancer and respective prognostic prediction

Additional file 2: Fig. S2. (A) The comparison of immune infiltration levels between high-risk and low-risk groups in L_cancer patients, based on CIBERSORT. (B) The Stromal Score difference, Immune Score difference, ESTIMATE Score difference, and tumor purity difference between high-risk and low-risk groups in L_cancer patients. (C) The immune checkpoint-related gene expression levels in high-risk and low-risk groups in L_cancer patients. (D) The tumor mutation burden difference between high-risk and low-risk groups in L_cancer patients. (E) HLA-related gene expression level between high-risk and low-risk groups in L_cancer patients. (Notes: ns P>0.05)