Resistance to tumor-necrosis-factor-related apoptosis-inducing ligand (TRAIL) of cancer cell remains a key obstacle for clinical cancer therapies. To overcome TRAIL resistance, this study identifies curcumol as a novel safe sensitizer from a food-source compound library, which exhibits synergistic lethal effects in combination with TRAIL on non-small cell lung cancer (NSCLC). SILAC-based cellular thermal shift profiling identifies NRH:quinone oxidoreductase 2 (NQO2) as the key target of curcumol. Mechanistically, curcumol directly targets NQO2 to cause reactive oxygen species (ROS) generation, which triggers endoplasmic reticulum (ER) stress-C/EBP homologous protein (CHOP) death receptor (DR5) signaling, sensitizing NSCLC cell to TRAIL-induced apoptosis. Molecular docking analysis and surface plasmon resonance assay demonstrate that Phe178 in NQO2 is a critical site for curcumol binding. Mutation of Phe178 completely abolishes the function of NQO2 and augments the TRAIL sensitization. This study characterizes the functional role of NQO2 in TRAIL resistance and the sensitizing function of curcumol by directly targeting NQO2, highlighting the potential of using curcumol as an NQO2 inhibitor for clinical treatment of TRAIL-resistant cancers.

Background Cell invasion is a hallmark of metastatic cancer, leading to unfavorable clinical outcomes. In this study, we established two highly invasive lung cancer cell models (A549-i8 and H1299-i8) and identified mesoderm-specific transcript (MEST) as a novel invasive regulator of lung cancer. We aim to characterize its biological function and clinical significance in lung cancer metastasis. Methods Transwell invasion assay was performed to establish high-invasive lung cancer cell model. Immunohistochemistry (IHC) was used to detect MEST expression in tumor tissues. Mass spectrometry and bioinformatic analyses were used to identify MEST-regulated proteins and binding partners. Co-immunoprecipitation assay was performed to detect the interaction of MEST and VCP. The biological functions of MEST were investigated in vitro and in vivo. Immunofluorescence staining was conducted to explore the colocalization of MEST and VCP. Results MEST overexpression promoted metastasis of lung cancer cells in vivo and in vitro by activating NF-κB signaling. MEST increased the interaction between VCP and IκBα, which accelerated IκBα degradation and NF-κB activation. Such acceleration was abrogated by VCP silencing, indicating that MEST is an upstream activator of the VCP/IκBα/NF-κB signaling pathway. Furthermore, high expressions of MEST and VCP were associated with poor survival of lung cancer patients. Conclusion Collectively, these results demonstrate that MEST plays an important role in driving invasion and metastasis of lung cancer by interacting with VCP to coordinate the IκBα/NF-κB pathway. Targeting the MEST/VCP/IκBα/NF-κB signaling pathway may be a promising strategy to treat lung cancer.

Colorectal cancer (CRC) is one of the most lethal diseases with high morbidity and mortality worldwide. Clinically, tumors located in colon and rectum have diverse prognosis and therapeutic outcome. Here, we performed data mining derived from 20 CRC patient samples to compare proteomic difference between colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ). We found that differential expressed proteins (DEPs) upregulated in COAD were mainly enriched in immune response, moreover, higher immune scores were found in COAD than READ, as calculated by The Cancer Genome Atlas (TCGA) data. To identify the core protein of DEPs with high prognostic value for COAD, we performed topological overlap matrix (TOM) to investigate the hub proteins using 77 immune-relevant DEPs, and identified complement component 3 (C3) as the core protein in the immune-relevant DEPs matrix between the COAD and READ. Moreover, we found that C3 was up-regulated in COAD, and its expression was negatively associated with overall survival of COAD patients but not READ. In conclusion, we identified C3-mediated immune response as key feature to distinguish COAD and READ, and highlighted C3 as potential biomarker with high prognostic value for clinical application, which provided new clue for precise treatment of COAD.

Dephosphorylation of transcription factor EB (TFEB) at Ser142 and Ser138 determines its nuclear localization and transcriptional activity. The link between TFEB-associated genes and colorectal cancer (CRC) progression and prognosis remains unclear. To systematically identify the targets of TFEB, we performed data-independent acquisition (DIA)-based quantitative proteomics to compare global protein changes in wild-type (WT) DLD1 cells and TFEBWT- or TFEBS142A/S138A (activated status)-expressing DLD1 cells. A total of 6048 proteins were identified and quantified in three independent experiments. The differentially expressed proteins in TFEBS142A/S138A versus TFEBWT and TFEBWT versus control groups were compared, and 60 proteins were identified as products of TFEB transcriptional regulation. These proteins were significantly associated with vesicular endocytic trafficking, the HIF-1 signaling pathway, and metabolic processes. Furthermore, we generated a TFEB-associated gene signature using a univariate and LASSO Cox regression model to screen robust prognostic markers. An eight-gene signature (PLSCR3, SERPINA1, ATP6V1C2, TIMP1, SORT1, MAP2, KDM4B, and DDAH2) was identified. According to the signature, patients were assigned to high-risk and low-risk groups. Higher risk scores meant worse overall survival and higher epithelial–mesenchymal transition (EMT) scores. Additionally, as per the clinicopathological parameters and gene signature, a nomogram was constructed that was utilized to enhance the quantification capacity in risk assessment for individual patients. This research shows that TFEB directly mediates network effects in CRC, and the identified TFEB gene signature-based model may provide important information for the clinical judgment of prognosis.

Background: Colon cancer is one of the most common malignant cancers, and cancer metastasis always leads to a failure of clinical treatment. Although there have been many studies on the process of colon cancer progression, the detailed mechanism of colon cancer metastasis still remains unclear, and more effective drugs targeting colon cancer metastasis are urgently needed. This study aims to explore novel effectors involved in colon cancer metastasis and screen out potential targeted drug for colon cancer therapy.Methods: Mass spectrometry and bioinformatics analyses are performed to present the proteomics variation between two colon cancer cell lines with different invasion abilities. Boyden chamber invasion assay (in vitro) and experimental metastasis assay in mice (in vivo) are performed to explore the role of protein tyrosine phosphatase-like A domain containing 1 (PTPLAD1) in colon cancer metastasis. Western blotting and qRT-PCR assays are performed to analyze the expression of proteins and mRNA of related signaling cascades. Co-immunoprecipitation (Co-IP) and confocal assays are conducted to examine the proteins interacted with PTPLAD1. Chromatin-immunoprecipitation (ChIP) assay is fulfilled to evaluate the relationship of PTPLAD1 expression and histone H3K9 acetylation. Enzyme-linked immuno sorbent assay (ELISA) screening system are used to screen out the small molecular inhibitor that mimics the effect of PTPLAD1 on suppressing colon cancer metastasis.Results: Our results identify that PTPLAD1 is significantly downregulated in the highly invasive cell lines, and PTPLAD1 suppresses colon cancer metastasis by interacting with prohibitin (PHB) and prohibiting the activation of PHB/C-Raf1 (Raf)/ extracellular signal-regulated kinase (ERK)/Snail signaling pathway. Moreover, the expression of PTPLAD1 is modulated through the acetylation of histone H3K9. Besides, we identify a small molecule named avobenzone, once used to protect skin from ultraviolet damage, that can disrupt the interaction of PHB and Raf, significantly abrogate the activation of downstream signaling cascades and prohibit colon cancer metastasis.Conclusions: Collectively, our study not only identifies PTPLAD1 as a novel tumor suppressor and clarifies its role in suppressing colon cancer metastasis, but also provides a potential targeted drug for metastatic colon cancer therapy.