To investigate the effect of RAS on anti-EGFR moAb + 5-FU infusion based chemotherapy in first-line treatment of mCRC.

The epithelial-to-mesenchymal transition (EMT) is a well-known prerequisite for cancer cells to acquire the migratory and invasive capacity, and to subsequently metastasize. Bufalin is one of the major active components of the traditional Chinese medicine Chan Su, and accumulating evidence has shown its anticancer effect in multipe types of cancer. However, the role of bufalin in transforming growth factor‑β (TGF‑β)‑induced EMT and migration remains unclear. In the present study, the effect of bufalin on TGF‑β‑induced EMT and migration was investigated in human lung cancer A549 cells. TGF‑β induced EMT in A549 cells and increased their migratory ability, which were markedly suppressed by bufalin. Additionally, TGF‑β‑induced upregulation of Twist2 and zinc finger E‑box binding homeobox 2 (ZEB2), as well as the phosphorylation of Smad2 and Smad3 were also inhibited by bufalin. However, the Smad‑independent signaling pathways were not affected. Further analysis showed that the TGF‑β receptor I (TβRI) and TGF‑β receptor II (TβRII) were downregulated in the presence of bufalin. Pretreatment with SB431542, a potent inhibitor of the phosphorylation of TβRI, significantly attenuated TGF‑β‑induced EMT, mimicking the effect of bufalin on A549 cells. Taken together, these results suggest that bufalin suppresses TGF-β-induced EMT and migration by downregulating TβRI and TβRII in A549 cells.

Although anti-programmed death ligand-1 (PD-L1) therapy has shown light in treatment of gastric cancer, only a limited number of patients respond to the treatment. In addition to its immunosuppressive effect, PD-L1 is involved in other functions of tumor cells. Previously study showed that PD-L1 promoted EMT in lung cancer cells. However, the other effect and role of PD-L1 in gastric cancer remains unclear. In the present study, we first demonstrated that PD-L1 promoted the proliferation and migration in gastric cancer cell lines. We found that another STAT family member, STAT5a, is involved in regulating the expression of PD-L1 in gastric cancer. Additionally, Cbl-b interacted and ubiquitated STAT5a, down-regulated the expression of STAT5a and PD-L1. Moreover, bioinformatics predictions and experimental data showed that Cbl-b is a target gene of the microRNA miR-940. We further found that miR-940 promoted the proliferation and migration of gastric cancer in vivo and in vitro. Taken together, our findings suggest that miR-940/Cbl-b/STAT5a axis regulated the expression of PD-L1, which promotes the proliferation and migration of gastric cancer cells.

The ATR/checkpoint kinase 1 (Chk1) pathway plays an essential role in modulating the DNA damage response and homologous recombination. Particularly, Chk1 phosphorylation is related to cancer prognosis and therapeutic resistance. Some receptor tyrosine kinases participate in the regulation of Chk1 phosphorylation; however, the effect of hepatocyte growth factor (HGF) on Chk1 phosphorylation is unknown. In the present study, we demonstrated that HGF moderately activated Chk1 phosphorylation in colon cancer cells by upregulating TopBP1 and RAD51, and promoting TopBP1-ATR complex formation. Furthermore, AKT activity, which was promoted by HGF, served as an important mediator linking HGF/MET signaling and Chk1 phosphorylation. Depleting AKT activity attenuated basal expression of p-Chk1 and HGF-induced Chk1 activation. Moreover, AKT activity directly regulated TopBP1 and RAD51 expression. AKT inhibition suppressed HGF-induced upregulation of TopBP1 and RAD51, and enhanced TopBP1/ATR complex formation. Our results show that HGF was involved in regulating Chk1 phosphorylation, and further demonstrate that AKT activity was responsible for this HGF-induced Chk1 phosphorylation. These findings might potentially result in management of prognosis and therapeutic sensitivity in cancer therapy.

The abnormal m6A modification caused by m6A modulators is a common feature of various tumors; however, little is known about which m6A modulator plays the most important role in triple-negative breast cancer (TNBC). In this study, when analyzing the influence of m6A modulators (METTL3, METTL14, WTAP, FTO, and ALKBH5) on the prognosis of breast cancer, especially in TNBC using several on-line databases, methyltransferase-like 3 (METTL3) was found to have low expression in breast cancer, and was closely associated with short-distance-metastasis-free survival in TNBC. Further investigation showed that knockdown of METTL3 could enhance the ability of migration, invasion, and adhesion by decreasing m6A level in TNBC cell lines. Collagen type III alpha 1 chain (COL3A1) was identified and verified as a target gene of METTL3. METTL3 could down-regulate the expression of COL3A1 by increasing its m6A methylation, ultimately inhibiting the metastasis of TNBC cells. Finally, with immunohistochemistry staining in breast cancer tissues, it was proved that METTL3 expression was negatively correlated with COL3A1 in TNBC, but not in non-TNBC. This study demonstrated the potential mechanism of m6A modification in metastasis and provided potential targets for treatment in TNBC.

Gastric cancer (GC) is a common cause of cancer-related death worldwide. As a result of the lack of reliable diagnostic or prognostic biomarkers for GC, patient prognosis is still poor. Therefore, there is an urgent need for studies examining the underlying pathogenesis of GC in order to find effective biomarkers. LRRN1 (leucine-rich repeat neuronal protein-1) is a type I transmembrane protein that plays an important role in the process of nerve development and regeneration. However, its role in cancer, especially in GC, remains unclear. In the present study, we found that LRRN1 expression is upregulated in GC tissues and that high LRRN1 expression is associated with poor prognosis. siRNA and shRNA-mediated knockdowns of LRRN1 expression promoted GC cell apoptosis and activation of the Fas/FasL pathway. LRRN1 knockdown also resulted in upregulation of JUN, a subunit of the transcription factor AP-1 (activator protein-1). This suggests that LRRN1 suppresses GC cell apoptosis by downregulating AP-1, resulting in inhibition of the Fas/FasL pathway. These results confirm that LRRN1 plays a significant role in GC pathogenesis. Moreover, LRRN1 may be a potential prognostic biomarker and therapeutic target for GC.

Non-small-cell lung cancer (NSCLC) is the leading global cause of cancer-related death. Due to the lack of reliable diagnostic or prognostic biomarkers, the prognosis of NSCLC remains poor. Consequently, there is an urgent need to explore the mechanisms underlying this condition in order to identify effective biomarkers. G-protein-signaling modulator 2 (GPSM2) is widely recognized as a determinant of mitotic spindle orientation. However, its role in cancer, especially NSCLC, remains uncertain. In this study, we found that GPSM2 was downregulated in NSCLC tissues and was correlated with a poor prognosis. Furthermore, the knockdown of GPSM2 promoted NSCLC cell metastasis in vitro and in vivo and accelerated the process of epithelial-mesenchymal transition (EMT). Mechanistically, we showed that silencing GPSM2 induced cell metastasis and EMT through the ERK/glycogen synthase kinase-3β/Snail pathway. These results confirm that GPSM2 plays an important role in NSCLC. Moreover, GPSM2, as an independent prognostic factor, could be a potential prognostic biomarker and drug target for NSCLC.

BACKGROUND Serine proteinase inhibitor clade B member 3 (SERPINB3) is a neutral glycoprotein. Its overexpression is related to the promotion of cell proliferation and activation via the nuclear factor kappa B (NF-kappaB) pathway in several tumors. Whether it can participate in stromal cell-derived factor (SDF-1)/NF-kappaB-induced metastasis of gastric cancer has not been reported. MATERIAL AND METHODS We analyzed the ability of SDF-1 to induce migration and invasion in vitro by knocking down the expression of SERPINB3 with siRNAs in gastric cancer cells. We also explored the effects of a CXCR4 antagonist and NF-kappaB inhibitor on SERPINB3 expression. We verified the effect of SERPINB3 on prognosis in gastric cancer specimens by immunohistochemistry. RESULTS In vitro experiments confirmed that SDF-1 upregulated the expression of SERPINB3 and promoted metastasis in gastric cancer cells. This phenomenon was reversed by knockdown of SERPINB3, a chemokine receptor 4 (CXCR4) antagonist, and an NF-kappaB inhibitor, which downregulated the expression of SERPINB3. In patients with gastric cancer, a significant positive correlation was observed between CXCR4 and SERPINB3 expression (r=0.222, P=0.029). Moreover, double positivity for SERPINB3 and CXCR4 was certified to be an independent prognostic factor (HR=3.332, P<0.001). CXCR4-positive patients who also expressed SERPINB3 were inclined to suffer from lymph node metastasis, confirming that SERPINB3 is a downstream molecule of CXCR4. CONCLUSIONS In vitro and pathological results showed that SDF-1/CXCR4 activated the NF-kappaB pathway and upregulated SERPINB3 to facilitate the migration and invasion of gastric cancer cells.

Patients with non-small cell lung cancer (NSCLC) treated with EGFR-tyrosine kinase inhibitors (TKIs) ultimately develop drug resistance and metastasis. Therefore, there is a need to identify the underlying mechanisms of resistance to EGFR-TKIs. In the present study, colony formation and MTT assays were performed to investigate cell viability following treatment with icotinib. Gene Expression Omnibus datasets were used to identify genes associated with resistance. Wound healing and Transwell assays were used to detect cell migration and invasion with icotinib treatment and integrin α5-knockdown. The expression levels of integrin α5 and downstream genes were detected using western blotting. Stable icotinib-resistant (IcoR) cell lines (827/IcoR and PC9/IcoR) were established that showed enhanced malignant properties compared with parental cells (HCC827 and PC9). Furthermore, the resistant cell lines were resistant to icotinib in terms of proliferation, migration and invasion. The enrichment of function and signaling pathways analysis showed that integrin α5-upregulation was associated with the development of icotinib resistance. The knockdown of integrin α5 attenuated the migration and invasion capability of the resistant cells. Moreover, a combination of icotinib and integrin α5 siRNA significantly inhibited migration and partly restored icotinib sensitivity in IcoR cells. The expression levels of phosphorylated (p)-focal adhesion kinase (FAK), p-STAT3 and p-AKT decreased after knockdown of integrin α5, suggesting that FAK/STAT3/AKT signaling had a notable effect on the resistant cells. The present study revealed that the integrin α5/FAK/STAT3/AKT signaling pathway promoted icotinib resistance and malignancy in IcoR NSCLC cells. This signaling pathway may provide promising targets against acquired resistance to EGFR-TKI in patients with NSCLC.

Background: Breast cancer is one of the most frequent malignant tumors worldwide, with 1.67 million newly-diagnosed cases and 522,000 deaths each year. Therefore, seeking the novel biomarkers and therapeutic targets that contribute to postoperative recurrence and metastasis in patients with breast cancer is emerging and facilitates the development of innovative therapeutics. Methods: Retrieving the dataset of patients with hormone receptor (HR)-positive breast cancers from Gene Expression Omnibus (GEO) and collecting the data from the patients with HR-positive breast cancers enrolled in the First Affiliated Hospital of China Medical University are so as to identify the miRNAs associated with metastasis and distant metastasis-free survival (DMFS). Then MTT and Transwell migration assays were used to validate the effect of miRNAs on cell proliferation and migration of estrogen receptor-positive breast cancer T47D and MCF7 cells in vitro, respectively. Results: From GSE59829 dataset, the miRNA expression levels of miR-891a-5p, miR-383-5p and miR-1295a were significantly downregulated while the levels of miR-128-3p, miR-661 and miR-296-3p were significantly upregulated in breast cancers from patients with metastasis as compared to the matched non-metastatic group. Moreover, low expression levels of miR-891a-5p, miR-383-5p and miR-1295a or high expression levels of miR-128-3p, miR-661 and miR-296-3p were respectively associated with low DMFS in patients with breast cancer. Our clinical cohort study supported that the levels of miR-891a-5p, miR-383-5p and miR-1295a were significantly lower in breast cancers from the metastasis group when compared with non-metastatic group. However, there is no significant difference with regard to the levels of miR-128-3p, miR-661 and miR-296-3p in breast cancer between these two groups. Moreover, low expression levels of miR-891a-5p and miR-383-5p but not miR-1295a in breast cancer were significantly associated with low DMFS in patients, implying that the expression of miR-891a-5p and miR-383-5p were the potential prognosis markers for metastatic human breast cancers. Further investigation disclosed that miR-891a-5p but not miR-383-5p restrained both proliferation and migration of T47D and MCF7 cells. In silico analysis of miRNAs target gene through online computational algorithms revealed that A Disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) is the downstream target for miR-891a-5p. Further study confirmed that miR-891a-5p impeded ADAM10 expression by directly binding to its 3'UTR, leading to the inhibition of breast cancer cells proliferation and migration. Moreover, silencing ADAM10 inhibited T47D and MCF7 cells growth and migration. Conclusion: miR-891a-5p is the vital prognostic marker for HR-positive breast cancer. In addition, miR-891a-5p and miR-383-5p are the potential targets for HR-positive breast cancer therapeutics.

MicroRNAs (miRNAs) are known to be involved in the development and progression of pancreatic cancer (PC). In this study, the prognostic significance and mechanistic role of microRNA-569 in PC were explored. Quantitative real-time PCR was used to detect the expression of microRNA-569 in PC tissues and cell lines. Scratch test and Transwell assay were conducted to detect migration and invasion ability. The xenograft nude mice model was used to determine tumor metastasis in vivo. The direct targets of microRNA-569 were determined by using bioinformatics analysis and a dual-luciferase reporter assay. The expression level of microRNA-569 was down-regulated in PC patients with a poor prognosis. In vitro and in vivo experiments indicated that over-expression of microRNA-569 inhibited the migration and invasion of PC cells. MicroRNA-569 negatively regulated NUSAP1 by directly binding its 3'-untranslated region. Further mechanism research implied that the ZEB1 pathway was involved in microRNA-569/NUSAP1 mediation of the biological behaviors in PC. These data demonstrated that microRNA-569 may exert a tumor-suppressing effect in PC and maybe a potential therapeutic target for PC patients.

Colorectal cancers (CRCs) with the BRAF V600E mutation exhibit upregulation of programmed death ligand 1 (PD-L1) but fail to respond to immunotherapy targeting programmed cell death protein 1 (PD-1)/PD-L1. Recent studies have explored the intracellular functions of PD-L1. Here, we demonstrate that PD-L1 was highly expressed in both the cytoplasm and nucleus of BRAF-mutated CRC tumor cells and tissues. Nuclear PD-L1 (nPD-L1) promoted the growth of tumor cells both in vitro and in vivo. Mechanistic investigations revealed that PD-L1 translocation into the nucleus was facilitated by the binding of p-ERK. Further, nPD-L1 upregulated the expression of cell cycle regulator BUB1 via interactions with thyroid hormone receptor-associated protein 3 (THRAP3), thereby accelerating cell cycle progression and promoting cell proliferation. Moreover, BRAF V600E-mutated CRC cells exhibited upregulation of PD-L1 expression via the transcription factor LEF-1. These findings reveal a novel role of nPD-L1, which promotes cell cycle progression in an immune-independent manner in BRAF V600E-mutated CRC. Our study provides novel insight into the mechanisms underlying BRAF V600E-mutated CRC progression.

Aldehyde dehydrogenase 3A1 (ALDH3A1) is an NAD+-dependent enzyme that is closely related to tumor development. However, its role in non-small-cell lung cancer (NSCLC) has not been elucidated. This study aimed to clarify the mechanism of ALDH3A1 and identify potential therapeutic targets for NSCLC. Here, for the first time, we found that ALDH3A1 expression could be induced by a hypoxic environment in NSCLC. ALDH3A1 was highly expressed in NSCLC tissue, especially in some late-stage patients, and was associated with a poor prognosis. In mechanistic terms, ALDH3A1 enhances glycolysis and suppresses oxidative phosphorylation (OXPHOS) to promote cell proliferation by activating the HIF-1α/LDHA pathway in NSCLC. In addition, the results showed that ALDH3A1 was a target of β-elemene. ALDH3A1 can be downregulated by β-elemene to inhibit glycolysis and enhance OXPHOS, thus suppressing NSCLC proliferation in vitro and in vivo. In conclusion, hypoxia-induced ALDH3A1 is related to the energy metabolic status of tumors and the efficacy of β-elemene, providing a new theoretical basis for better clinical applications in NSCLC.

This study aimed to investigate the effect of NPTX1 on the prognosis of gastric cancer (GC), as well as the metastatic process in GC.

5-Florouracil (5-FU) is the basic agent used in the treatment of gastric cancer. Capecitabine, a prodrug of 5-FU, displays increased antitumor efficacy compared with 5-FU in the clinic. 5'-Deoxy-5-fluorouracil (5'-DFUR), the metabolite of capecitabine, is converted to 5-FU by the enzyme thymidine phosphorylase (TP), which is present at high concentrations in human tumors. In this study, we investigated the effect of interferon-α (IFN-α) on the sensitivity of gastric cancer cells to treatment with 5'-DFUR and its relationship with TP expression. Preincubation of gastric cancer cells with IFN-α enhanced 5'-DFUR-induced apoptosis via IFN-α-mediated upregulation of TP. The depletion of TP with small interfering RNA (siRNA) obviously inhibited IFN-α-induced upregulation of TP expression and thus prevented apoptosis induced by IFN-α and 5'-DFUR. Treatment with IFN-α and combined IFN-α and 5'-DFUR treatment were also associated with concomitant activation of ERK signaling. Treatment with the ERK inhibitor PD98059 or depletion of ERK with siRNA partially reversed IFN-α-induced upregulation of TP expression, thus partially preventing apoptosis induced by IFN-α and 5'-DFUR. Taken together, our study shows that IFN-α enhanced 5'-DFUR-induced apoptosis in gastric cancer cells by upregulation of TP expression, which is partially regulated by activation of ERK signaling.

Ubiquitination of caspase-8 regulates TNF-related apoptosis-inducing ligand (TRAIL) sensitivity in cancer cells, and the preligand assembly complex plays a role in caspase-8 polyubiquitination. However, whether such a complex exists in gastric cancer cells and its role in TRAIL-triggered apoptosis is unclear. In this study, DR5, casitas B-lineage lymphoma-b (Cbl-b)/c-Cbl, and TRAF2 formed a complex in TRAIL-resistant gastric cancer cells, and Cbl-b and c-Cbl were the critical adaptors linking DR5 and TRAF2. Treatment with TRAIL induced caspase-8 translocation into the DR5-Cbl-b/c-Cbl-TRAF2 complex to interact with TRAF2, which then mediated the K48-linked polyubiquitination of caspase-8. The proteasome inhibitor bortezomib markedly enriched the p43/41 products of caspase-8 activated by TRAIL, indicating proteasomal degradation of caspase-8. Moreover, TRAF2 knockdown prevented the polyubiquitination of caspase-8 and thus increased TRAIL sensitivity. In addition, the inhibition of Cbl-b or c-Cbl expression and overexpression of miR-141 targeting Cbl-b and c-Cbl partially reversed TRAIL resistance by inhibiting the interaction between TRAF2 and caspase-8 and the subsequent polyubiquitination of caspase-8. These results indicate that the DR5-Cbl-b/c-Cbl-TRAF2 complex inhibited TRAIL-induced apoptosis by promoting TRAF2-mediated polyubiquitination of caspase-8 in gastric cancer cells.

The aberrant expression of DNA methyltransferases (DNMTs) has been considered to be associated with pancreatic carcinogenesis and progression. DNMT3a is widely involved in cell proliferation and cell cycle progression in pancreatic ductal adenocarcinoma (PDAC) cells. However, its regulation of chemosensitivity to gemcitabine (GEM) and oxaliplatin (OXA) in p53‑deficient PDAC remains unclear. In the present study, the effect and mechanisms of DNMT3a on GEM and OXA chemosensitivity in p53‑deficient PDAC cells were investigated using MTT assay, cell cycle analysis, apoptosis analysis and western blotting. The treatment of GEM and OXA induced S phase arrest by DNA damage, and enhanced the activation of the AKT signaling pathway in Panc‑1 cells. Downregulation of DNMT3a increased the chemosensitivity to both GEM and OXA in Panc‑1 cells. DNMT3a depletion distinctly abolished S phase arrest induced by GEM and OXA. Further research demonstrated that activation inhibition of CHK1 and AKT, as well as an increase in apoptosis, were involved in DNMT3a‑mediated chemosensitivity to GEM and OXA. Taken together, these data demonstrated that DNMT3a serves a crucial role in the regulation of chemosensitivity to GEM and OXA, and suggests a promising therapeutic target for p53‑deficient PDAC.

Tamoxifen is a frontline therapy for estrogen receptor (ER)-positive breast cancer in premenopausal women. However, many patients develop resistance to tamoxifen, and the mechanism underlying tamoxifen resistance is not well understood. Here we examined whether ER-c-Src-HER2 complex formation is involved in tamoxifen resistance.

Anti-PD-1 therapy has been approved for cancer treatment. However, the response rate is unsatisfactory. The expression of PD-L1 in tumor tissues is unreliable to predict the treatment response. Recent studies have suggested that exosomal PD-L1 not only exerts immunosuppressive effects but also plays a significant role in the development of tumor microenvironment. Thus, the present study aims to investigate exosomal PD-L1 in improving its predictive value and efficacy. A total of 44 patients of advanced tumors of several types, treated with anti-PD-1 therapy, were enrolled. Exosomes were collected and purified from plasma. The exosomal PD-L1 was detected with ELISA. The cytokines were measured with the MILLIPLEX magnetic bead assay. Compared to the responders, exosomal PD-L1 of the non-responders was significantly higher than that of the responders (P = 0.010) before the treatment. Concurrently, exosomal PD-L1 and tumor burden decreased when the therapy was effective. And, the baseline expression of CD28 was higher in the responders than that in the non-responders (P = 0.005). Univariate and multivariate analyses validated with 1,000 times bootstrapping suggested that high exosomal PD-L1 and low CD28 expressions were negative factors for progression-free survival (PFS) of the patients who underwent anti-PD-1 treatment. The combination of exosomal PD-L1 and CD28 obtained more area under the curve (AUC) of receiver operating characteristic (ROC) (AUC 0.850 vs. 0.784 vs. 0.678) and showed a higher probability of no progression via nomograph. These findings suggested that the expression of exosomal PD-L1 and CD28 could serve as the predictive biomarkers for clinical responses to anti-PD-1 treatment.

The mutational profile of oncogenic driver genes play an important role in non-small-cell lung cancer (NSCLC). The need of a testing panel capable of comprehensively determining patient genotypes in limited amounts of material has increased since the recent association of nine core oncogenic driver genes as tumor predictive biomarkers.