Immune Activation Effects at Different Irradiated Sites and Optimal Timing of Radioimmunotherapy in Patients with Extensive-Stage Small Cell Lung Cancer: a Real-World Analysis.

BACKGROUND: In view of the limited data on radiotherapy (RT) combined with immunotherapy in patients with extensive-stage small cell lung cancer (ES-SCLC), this study aimed to identify the immune activation effect on different sites and the survival outcomes of radioimmunotherapy at different treatment stages. METHODS: Forty-five patients diagnosed with ES-SCLC were included in this retrospective analysis. We collected the overall survival (OS) of the patients,, recorded the blood cell counts before, during, and after RT, and derived blood index ratios such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII). The datasets were analyzed using the Spearman rank correlation test, Kruskal-Wallis rank sum test and logistic regression. RESULTS: Among the selected blood indices, the delta-NLR/PLR/Sll correlated with different irradiated organs, and the mean ranks of these three indices were the lowest in the brain-irradiated group during immunotherapy. Additionally, adjunct first-line immunotherapy with RT demonstrated a significant improvement compared to second- or third-line therapy and subsequent therapies. CONCLUSION: Our findings suggest that compared to other organs, the strongest immune activation effect occurs with brain RT, and ES-SCLC patients who received radioimmunotherapy (RIT) earlier achieved higher OS rates.

HER3 functions as an effective therapeutic target in triple negative breast cancer to potentiate the antitumor activity of gefitinib and paclitaxel.

BACKGROUND: Triple negative breast cancer (TNBC) represents a significant clinical challenge. Chemotherapy remains the mainstay for a large part of TNBC patients, whereas drug resistance and tumor recurrence frequently occur. It is in urgent need to identify novel molecular targets for TNBC and develop effective therapy against the aggressive disease. METHODS: Immunohistochemistry was performed to examine the expression of HER3 in TNBC samples. Western blots were used to assess protein expression and activation. Cell proliferation and viability were determined by cell growth (MTS) assays. TCGA databases were analyzed to correlate HER3 mRNA expression with the clinical outcomes of TNBC patients. Specific shRNA was used to knockdown HER3 expression. IncuCyte system was utilized to monitor cell growth and migration. LIVE/DEAD Cell Imaging was to detect live and dead cells. HER3 recognition by our anti-HER3 monoclonal antibody (mAb) 4A7 was verified by ELISA, flow cytometry, and co-immunoprecipitation assays. Orthotopic tumor models were established in nude mice to determine the capability of TNBC cells forming tumors and to test if our mAb 4A7 could potentiate the antitumor activity of paclitaxel in vivo. RESULTS: Elevated expression of HER3 was observed in approximately half of the TNBC specimens and cell lines tested. Analyses of TCGA databases found that the TNBC patients with high HER3 mRNA expression in the tumors showed significantly worse overall survival (OS) and relapse-free survival (RFS) than those with low HER3 expression. Specific knockdown of HER3 markedly inhibited TNBC cell proliferation and mammosphere formation in vitro and tumor growth in vivo. Our mAb 4A7 abrogated heregulin (a ligand for HER3), but not SDF-1 (a ligand for CXCR4)-induced enhancement of TNBC cell migration. Combinations of 4A7 and the EGFR-tyrosine kinase inhibitor (TKI) gefitinib dramatically decreased the levels of phosphorylated HER3, EGFR, Akt, and ERK1/2 in TNBC cells and potently induced growth inhibition and cell death. Moreover, 4A7 in combination with paclitaxel exerted significant antitumor activity against TNBC in vitro and in vivo. CONCLUSIONS: Our data demonstrate that increased HER3 is an effective therapeutic target for TNBC and our anti-HER3 mAb (4A7) may enhance the efficacy of gefitinib or paclitaxel in TNBC.

Compensation of lens manufacturing errors and inhomogeneities by filtering view images in three-dimensional lenticular displays.

For a multiview autostereoscopic three-dimensional display based on the lenticular lens, the manufacturing errors and inhomogeneities of the lenticular sheet can deteriorate the view image quality. A calibration method is proposed by filtering the pixel mapping of all view images. Each view is first sequentially turned on to show a white test image, and the intensity distribution of every view will be analyzed. Then individual filter functions are derived and applied to the corresponding view images to correct the subpixel value. Experimental results show that the proposed method can solve view image loss and significantly improve the quality of stereoscopic images.

Transactivation of SOX5 by Brachyury promotes breast cancer bone metastasis.

The bone marrow has been long known to host a unique environment amenable to colonization by metastasizing tumor cells. Yet, the underlying molecular interactions which give rise to the high incidence of bone metastasis (BM) in breast cancer patients have long remained uncharacterized. In our study, in vitro and in vivo assays demonstrated that Brachyury (Bry) could promote breast cancer BM. Bry drives epithelial-mesenchymal transition (EMT) and promotes breast cancer aggressiveness. As an EMT driver, SOX5 involves in breast cancer metastasis and the specific function in BM. Chromatin immunoprecipitation (ChIP) assays revealed SOX5 is a direct downstream target gene of Bry. ChIP analysis and reporter assays identified two Bry-binding motifs; one consistent with the classic conserved binding sequence and the other a new motif sequence. This study demonstrates for the first time that Bry promotes breast cancer cells BM through activating SOX5. In clinical practice, targeting the Bry-Sox5-EMT pathway is evolving into a promising avenue for the prevention of bone metastatic relapse, therapeutic resistance and other aspects of breast cancer progression. Brachyury directly regulates the expression of SOX5 by binding to two motifs in its promoter region. The Bry-SOX5-EMT pathway may represent a potential target to develop treatments to prevent and treat bone metastasis from breast cancer.

p53-inducible gene 3 promotes cell migration and invasion by activating the FAK/Src pathway in lung adenocarcinoma.

The p53-inducible gene 3 (PIG3) is one of the p53-induced genes at the onset of apoptosis, which plays an important role in cell apoptosis and DNA damage response. Our previous study reported an oncogenic role of PIG3 associated with tumor progression and metastasis in non-small cell lung cancer (NSCLC). In this study, we further analyzed PIG3 mRNA expression in 504 lung adenocarcinoma (LUAD) and 501 lung squamous cell carcinoma (LUSC) tissues from The Cancer Genome Atlas database and we found that PIG3 expression was significantly higher in LUAD with lymph node metastasis than those without, while no difference was observed between samples with and without lymph node metastasis in LUSC. Gain and loss of function experiments were performed to confirm the metastatic role of PIG3 in vitro and to explore the mechanism involved in its oncogenic role in NSCLC metastasis. The results showed that PIG3 knockdown significantly inhibited the migration and invasion ability of NSCLC cells, and decreased paxillin, phospho-focal adhesion kinase (FAK) and phospho-Src kinase expression, while its overexpression resulted in the opposite effects. Blocking FAK with its inhibitor reverses PIG3 overexpression-induced cell motility in NSCLC cells, indicating that PIG3 increased cell metastasis through the FAK/Src/paxillin pathway. Furthermore, PIG3 silencing sensitized NSCLC cells to FAK inhibitor. In conclusion, our data revealed a role for PIG3 in inducing LUAD metastasis, and its role as a new FAK regulator, suggesting that it could be considered as a novel prognostic biomarker or therapeutic target in the treatment of LUAD metastasis.

MiR-592 Promotes Gastric Cancer Proliferation, Migration, and Invasion Through the PI3K/AKT and MAPK/ERK Signaling Pathways by Targeting Spry2.

BACKGROUND/AIMS: Gastric cancer (GC) is one of the most prevalent digestive malignancies. MicroRNAs (miRNAs) are involved in multiple cellular processes, including oncogenesis, and miR-592 itself participates in many malignancies; however, its role in GC remains unknown. In this study, we investigated the expression and molecular mechanisms of miR-592 in GC. METHODS: Quantitative real-time PCR and immunohistochemistry were performed to determine the expression of miR-592 and its putative targets in human tissues and cell lines. Proliferation, migration, and invasion were evaluated by Cell Counting Kit-8, population doubling time, colony formation, Transwell, and wound-healing assays in transfected GC cells in vitro. A dual-luciferase reporter assay was used to determine whether miR-592 could directly bind its target. A tumorigenesis assay was used to study whether miR-592 affected GC growth in vivo. Proteins involved in signaling pathways and the epithelial-mesenchymal transition (EMT) were detected with western blot. RESULTS: The ectopic expression of miR-592 promoted GC proliferation, migration, and invasion in vitro and facilitated tumorigenesis in vivo. Spry2 was a direct target of miR-592 and Spry2 overexpression partially counteracted the effects of miR-592. miR-592 induced the EMT and promoted its progression in GC via the PI3K/AKT and MAPK/ERK signaling pathways by inhibiting Spry2. CONCLUSIONS: Overexpression of miR-592 promotes GC proliferation, migration, and invasion and induces the EMT via the PI3K/AKT and MAPK/ERK signaling pathways by inhibiting Spry2, suggesting a potential therapeutic target for GC.

Phosphorylation of ETS-1 is a critical event in DNA polymerase iota-induced invasion and metastasis of esophageal squamous cell carcinoma.

An aberrantly elevated expression of DNA polymerase ι (Pol ι) is significantly associated with poor prognosis of patients with esophageal squamous cell carcinoma (ESCC), yet the mechanisms behind this phenomenon remain obscure. Based on the RNA-Seq transcriptome and real-time PCR analysis, we identified ETS-1 as a candidate gene involved in Pol ι-mediated progression of ESCC. Wound-healing and transwell assay indicated that downregulation of ETS-1 attenuates Pol ι-mediated invasiveness of ESCC. Signaling pathway analysis showed that Pol ι enhances ETS-1 phosphorylation at threonine-38 through the Erk signaling pathway in ESCC cells. Kaplan-Meier analysis, based on 93 clinical tissue samples, revealed that ETS-1 phosphorylation at threonine-38 is associated with poor prognosis of ESCC patients. The present study thus demonstrates that phosphorylation of ETS-1 is a critical event in the Pol ι-induced invasion and metastasis of ESCC.

Evaluation of the blood supply and efficacy of transcatheter arterial chemoembolization for patients with liver metastasis using 18F-fluorodeoxyglucose positron emission tomography/computed tomography.

Our study aims to evaluate the efficacy of transcatheter arterial chemoembolization in the treatment of patients with liver metastasis using integrated 18F-fluorodeoxyglucose positron emission tomography/computed tomography. A total of 97 liver metastasis patients treated by transcatheter arterial chemoembolization were enrolled in this study. The 18F-fluorodeoxyglucose positron emission tomography/computed tomography images of liver metastasis patients were collected before and after transcatheter arterial chemoembolization treatment. The efficacy of transcatheter arterial chemoembolization for the treatment of liver metastasis was evaluated according to the revised Response Evaluation Criteria in Solid Tumors guidelines. The receiver operating characteristic curve analysis was used to determine cut-off values of 18F-fluorodeoxyglucose positron emission tomography parameters (Tsuvmax, Tsuvmax/Lsuvmax, and Tsuvmax/Lsuvmean) for predicting the efficacy of transcatheter arterial chemoembolization. Progression-free survival and the incidence of postoperative complications were compared. Correlation of Tsuvmax, Tsuvmax/Lsuvmax, and Tsuvmax/Lsuvmean with blood supply and lipiodol deposition in the lesion was analyzed. Among three 18F-fluorodeoxyglucose positron emission tomography parameters, the receiver operating characteristic analysis showed that Tsuvmax/Lsuvmax with a cut-off value of 3.56 was the best predictor of transcatheter arterial chemoembolization efficacy. According to the cut-off value of Tsuvmax/Lsuvmax, liver metastasis patients were divided into the Tsuvmax/Lsuvmax ≤ 3.56 and Tsuvmax/Lsuvmax > 3.56 groups. Compared with the Tsuvmax/Lsuvmax > 3.56 group, the Tsuvmax/Lsuvmax ≤ 3.56 group showed a longer progression-free survival and a lower incidence of postoperative complications. The Tsuvmax, Tsuvmax/Lsuvmax, and Tsuvmax/Lsuvmean in the lesion with abundant blood supply were significantly lower than those in peripheral liver parenchyma, while the Tsuvmax, Tsuvmax/Lsuvmax, and Tsuvmax/Lsuvmean in the lesion with lack of blood supply were significantly higher than those in peripheral liver parenchyma. Spearman correlation analysis indicated that lipiodol deposition in the lesion was positively correlated with the Tsuvmax, Tsuvmax/Lsuvmax, and Tsuvmax/Lsuvmean. The Tsuvmax/Lsuvmax of 18F-fluorodeoxyglucose positron emission tomography/computed tomography may be a good tool for predicting the blood supply and efficacy of transcatheter arterial chemoembolization for patients with liver metastasis.

[Effect of RAD18-siRNA on proliferation and chemotherapy sensitivity of human esophageal squamous cell carcinoma ECA-109 cells].

Objective: To investigate the effect of RAD18-siRNA on cell proliferation and chemotherapy sensitivity of esophageal squamous cell carcinoma (ESCC) ECA-109 cells. Methods: RAD18-siRNA was transfected into human ECA-109 cells by Lipofectamine 3000. Quantitative PCR and Western blot were performed to detect RAD18 and CyclinD1 expression; CCK-8 assay was used to determine cell proliferation and chemotherapy drug sensitivity; flow cytometry was used to determine cell cycle. Correlation between RAD18 and CyclinD1 mRNA expression was analyzed by Pearson's correlation. Results: Compared with non-transfected cells, the expression of RAD18 in RAD18-siRNA group was significantly decreased (P<0.05). The cell proliferation was inhibited (P<0.05) and the cell number of G1 phase was increased, G2/M phase cells decreased (P<0.05) in RAD18-siRNA group. After treatment with different concentrations of cisplatin or 5-FU, the survival rate of the two cell groups was reduced (all P<0.05), and the IC50 of RAD18-siRNA group was significantly lower than that of non-transfected group (P<0.05). The mRNA expression of RAD18 was positively correlated with CyclinD1 expression in ESCC tissues(r=0.478, P<0.01). Conclusion: Down-regulated expression of RAD18 can decrease the cell proliferation and increase chemo-sensitivity of ESCC cells, and CyclinD1 may participate in the process.

Upregulation of PAX2 promotes the metastasis of esophageal cancer through interleukin-5.

BACKGROUND/AIMS: This study investigated the clinical relevance and biological function of paired box gene 2 (PAX2) in esophageal squamous cell carcinoma (ESCC). METHODS/RESULTS: Results showed that PAX2 expression was significantly increased in tumor tissues and that its expression correlated with the ESCC stage (P = 0.001), lymph node metastasis (pN, P = 0.019) and lymphatic invasion (P = 0.005) in 120 ESCC tissue specimens by immunohistochemistry. Furthermore, PAX2 overexpression resulted in markedly reduced cell proliferation but increased metastasis capacity in ESCC TE-1 and Eca-109 cells. Knockdown of PAX2 expression with a short hairpin RNA confirmed a role in the promotion of metastasis in ESCC cells. mRNA microarray screening revealed that PAX2 overexpression affected multiple genes that function in multiple pathways. Interleukin-5 (IL-5), which was induced by PAX2 and has been shown to promote tumor metastasis, was further studied in greater detail. Two PAX2 binding sites were identified in the IL-5 promoter, and PAX2 was observed to stimulate IL-5 promoter activity and IL-5 expression in esophageal cancer cells. Chromatin immunoprecipitation (ChIP) confirmed the direct binding of PAX2 in the IL-5 promoter. The expression of PAX2 mRNA significantly correlated with that of IL-5 in normal esophageal and ESCC tissues. CONCLUSION: These findings demonstrate that PAX2 is overexpressed in esophageal carcinoma and IL-5 is identified as PAX2's effector for metastasis.

MiRNA-30a-mediated autophagy inhibition sensitizes renal cell carcinoma cells to sorafenib.

Chemotherapy-induced autophagy activation often contributes to cancer resistance. MiRNA-30a (miR-30a) is a potent inhibitor of autophagy by downregulating Beclin-1. In this study, we characterized the role of miR-30a in sorafenib-induced activity in renal cell carcinoma (RCC) cells. We found that expression of miR-30a was significantly downregulated in several human RCC tissues and in RCC cell lines. Accordingly, its targeted gene Beclin-1 was upregulated. Sorafenib activated autophagy in RCC cells (786-0 and A489 lines), evidenced by p62 degradation, Beclin-1/autophagy protein 5 (ATG-5) upregulation and light chain (LC)3B-I/-II conversion. Exogenously expressing miR-30a in 786-0 or A489 cells inhibited Beclin-1 expression and enhanced sorafenib-induced cytotoxicity. In contrast, knockdown of miR-30a by introducing antagomiR-30a increased Beclin-1 expression, and inhibited sorafenib-induced cytotoxicity against RCC cells. Autophagy inhibitors, including chloroquine, 3-methyaldenine or Bafliomycin A1, enhanced sorafenib activity, causing substantial cell apoptosis. Meanwhile, knockdown of Beclin-1 or ATG-5 by targeted siRNAs also increased sorafenib-induced cytotoxicity in above RCC cells. These findings indicate that dysregulation of miR-30a in RCC may interfere with the effectiveness of sorafenib-mediated apoptosis by an autophagy-dependent pathway, thus representing a novel potential therapeutic target for RCC.

LYTAK1, a novel TAK1 inhibitor, suppresses KRAS mutant colorectal cancer cell growth in vitro and in vivo.

KRAS mutation in colorectal cancer (CRC) activates transforming growth factor-ß (TGF-ß)-activated kinase 1 (TAK1) to promote tumor progression. In the current study, we explored the potential effect of LYTAK1, a novel TAK1 inhibitor, against KRAS mutant CRC cells in vitro and in vivo. We found that LYTAK1 dose-dependently inhibited KRAS mutant CRC cell (HT-29 and SW-620 lines) growth, and induced cell cycle G1-S arrest. Further, LYTAK1 activated apoptosis in HT-29 cells and SW-620 cells, and apoptosis inhibitors almost reversed LYTAK1-mediated growth inhibition. While in KRAS wild-type (WT) CRC cell lines (DLD-1 and HCT-116), LYTAK1 had almost no effect on cell growth, cell cycle progression, or cell apoptosis. In KRAS mutant HT-29 cells and SW-260 cells, LYTAK1 blocked TAK1 activation or phosphorylation at Thr-184/187. Activation of nuclear factor κB (NF-κB) in these cells, detected by phosphorylations of p65 and IκB kinase α (IKKα) as well as expression of NF-κB-regulated gene cyclin D1, was significantly inhibited by LYTAK1. Further, LYTAK1 treatment resulted in downregulation of ß-catenin and Wnt response gene Axin 2, indicating Wnt inactivation. In vivo, oral LYTAK1 significantly inhibited HT-29 xenograft growth in nude mice. Together, these results show that LYTAK1 inhibits KRAS mutant CRC cell growth both in vitro and in vivo. LYTAK1 might be investigated as a novel agent against CRC with KRAS mutation.

Proteasome inhibitor MG132 enhances the antigrowth and antimetastasis effects of radiation in human nonsmall cell lung cancer cells.

The current treatment for advanced nonsmall cell lung cancer (NSCLC) remains unsatisfactory due to resistance to chemotherapy and ionizing radiation. The ubiquitin-proteasome system (UPS) regulates multiple cellular processes that are crucial for the proliferation and survival of all kinds of cells. Carbobenzoxyl-leucinyl-leucinyl-leucinal-H (MG132), a specific and selective reversible inhibitor of the 26S proteasome, represents a novel approach for cancer therapy. However, whether MG132 can potentiate the effect of radiation against the growth and metastasis of NSCLC is not clear. We found that MG132 inhibited the proliferation of human NSCLC cell lines (A549 and H1299) in a dose- and time-dependent manner by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Then MG132 at a nontoxic dose (100 nM) was selected for following studies. Pretreatment of A549 and H1299 cells with 100 nM MG132 before ionizing radiation (IR) potentiated the anticancer effect of IR. Moreover, pretreatment with 100 nM MG132 before IR-enhanced radiation induced cell cycle arrest by decreased CyclinD1 but increased Wee1 expression in A549 and H1299 cells. In addition, pretreatment of MG132 combined with IR significantly suppressed cell migration and invasion abilities in NSCLC cell lines, which was accompanied by decreased expression of matrix metalloproteinase (MMP)-2 and MMP-9 in NSCLC cell lines. Taken together, our results demonstrate that MG132 enhances the antigrowth and antimetastatic effects of irradiation in NSCLC cells by modulating expression of cell cycle and invasion- related genes.

Amelioration of radiation-induced skin injury by HIV-TAT-mediated protein transduction of RP-1 from Rana pleurade.

Radiation-induced reactive oxygen species (ROS) can damage DNA and most other biological macromolecules in skin and radiation-induced skin injury is a serious concern for radiation therapy. Skin possesses an extremely efficient antioxidant system, which is conferred by two systems: antioxidant enzymes and small molecules that can scavenge ROS by donating electrons. Amphibian skin is a multifunctional organ, which protects against dangers of various oxidative stresses. Recently, a small peptide called RP-1 was isolated from the skin secretions of Rana pleurade, which shows strong antioxidant activity. However, this RP-1 peptide is limited because its inability to across the cell membrane. Protein transduction domains (PTDs) have demonstrated high efficiency for facilitating the internalization of both homologous and heterogeneous proteins into cells. This study aims to elucidate the protective effects of a HIV-TAT (TAT) PTD-coupled RP-1 fusion protein (TAT-RP1) on radiation-induced skin injury in vitro and in vivo. The synthesized fusion TAT-RP1 peptide can be incorporated into human keratinocyte HaCaT cells in a dose- and time-dependent manner without cytotoxicity. We then evaluated the protective role of TAT-RP1 against ionizing radiation. TAT-RP1 supplementation increased anti-superoxide anion ability of HaCaT cells and decreased HaCaT cell radiosensitivity to irradiation. Moreover, TAT-RP1 was able to penetrate the skin of rats, entering epidermis as well as the dermis of the subcutaneous layer in skin tissue. Topical spread of TAT-RP1 promoted the amelioration of radiation-induced skin damage in rats. These results suggest that TAT-RP1 has potential as a protein therapy for radiation-induced skin injury.

OoD-Control: Generalizing Control in Unseen Environments.

Generalizing out-of-distribution (OoD) is critical but challenging in real applications such as unmanned aerial vehicle (UAV) flight control. Previous machine learning-based control has shown promise in dealing with complex real-world environments but suffers huge performance degradation facing OoD scenarios, posing risks to the stability and safety of UAVs. In this paper, we found that the introduced random noises during training surprisingly yield theoretically guaranteed performances via a proposed functional optimization framework. More encouragingly, this framework does not involve common Lyapunov assumptions used in this field, making it more widely applicable. With this framework, the upperbound for control error is induced. We also proved that the induced random noises can lead to lower OoD control errors. Based on our theoretical analysis, we further propose OoD-Control to generalize control in unseen environments. Numerical experiments demonstrate the superiority of the proposed algorithm, surpassing previous state-of-the-art by 65% under challenging unseen environments. We further extend to outdoor real-world experiments and found that the control error is reduced by 50% approximately.

DNA polymerase iota promotes EMT and metastasis of esophageal squamous cell carcinoma by interacting with USP7 to stabilize HIF-1α.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancer types, with a low 5-year survival rate of ~20%. Our prior research has suggested that DNA Polymerase iota (Pol ι), a member of Y-family DNA polymerase, plays a crucial role in the invasion and metastasis of ESCC. However, the underlying mechanism is not well understood. In this study, we utilized ChIP-PCR and luciferase reporter assays to investigate the binding of HIF-1α to the promoter of the Pol ι gene. Transwell, wound healing, and mouse models were employed to assess the impact of Pol ι and HIF-1α on the motility of ESCC cells. Co-immunoprecipitation and Western blot were carried out to explore the interaction between Pol ι and HIF-1α, while qRT-PCR and Western blot were conducted to confirm the regulation of Pol ι and HIF-1α on their downstream targets. Our results demonstrate that HIF-1α activates the transcription of the Pol ι gene in ESCC cells under hypoxic conditions. Furthermore, the knockdown of Pol ι impeded HIF-1α-induced invasion and metastasis. Additionally, we found that Pol ι regulates the expression of genes involved in epithelial-mesenchymal transition (EMT) and initiates EMT through the stabilization of HIF-1α. Mechanistically, Pol ι maintains the protein stability of HIF-1α by recruiting USP7 to mediate the deubiquitination of HIF-1α, with the residues 446-578 of Pol being crucial for the interaction between Pol ι and USP7. Collectively, our findings unveil a novel feedforward molecular axis of HIF-1α- Pol ι -USP7 in ESCC that contributes to ESCC metastasis. Hence, our results present an attractive target for intervention in ESCC.

Activation of peroxisome proliferator-activated receptor α (PPARα) suppresses hypoxia-inducible factor-1α (HIF-1α) signaling in cancer cells.

Activation of peroxisome proliferator-activated receptor α (PPARα) has been demonstrated to inhibit tumor growth and angiogenesis, yet the mechanisms behind these actions remain to be characterized. In this study, we examined the effects of PPARα activation on the hypoxia-inducible factor-1α (HIF-1α) signaling pathway in human breast (MCF-7) and ovarian (A2780) cancer cells under hypoxia. Incubation of cancer cells under 1% oxygen for 16 h significantly induced HIF-1α expression and activity as assayed by Western blotting and reporter gene analysis. Treatment of the cells with PPARα agonists, but not a PPARγ agonist, prior to hypoxia diminished hypoxia-induced HIF-1α expression and activity, and addition of a PPARα antagonist attenuated the suppression of HIF-1α signaling. Activation of PPARα attenuated hypoxia-induced HA-tagged HIF-1α protein expression without affecting the HA-tagged HIF-1α mutant protein level, indicating that PPARα activation promotes HIF-1α degradation in these cells. This was further confirmed using proteasome inhibitors, which reversed PPARα-mediated suppression of HIF-1α expression under hypoxia. Using the co-immunoprecipitation technique, we found that activation of PPARα enhances the binding of HIF-1α to von Hippel-Lindau tumor suppressor (pVHL), a protein known to mediate HIF-1α degradation through the ubiquitin-proteasome pathway. Following PPARα-mediated suppression of HIF-1α signaling, VEGF secretion from the cancer cells was significantly reduced, and tube formation by endothelial cells was dramatically impaired. Taken together, these findings demonstrate for the first time that activation of PPARα suppresses hypoxia-induced HIF-1α signaling in cancer cells, providing novel insight into the anticancer properties of PPARα agonists.

Clofibrate induces heme oxygenase 1 expression through a PPARα-independent mechanism in human cancer cells.

BACKGROUND AND AIMS: Clofibrate, an established PPARα ligand, has recently been shown to have anticancer activity yet its mechanisms of action remain to be characterized. This study examined the effect of clofibrate on heme oxygenase-1 (HO-1) gene expression in A2780 (human ovarian cancer) and DU145 (human prostate cancer) cells. METHODS AND RESULTS: We demonstrate that clofibrate induces HO-1 expression in a concentration- and time-dependent manner. The induction of HO-1 by clofibrate was detected at both mRNA and protein levels and the HO-1 gene promoter activity was also dramatically induced by clofibrate, indicating that clofibrate up-regulates HO-1 gene transcription. Surprisingly, the induction of HO-1 by clofibrate was mediated by the Nrf2 signaling pathway, not by the PPARα pathway. This was primarily demonstrated by siRNA knockdown of Nrf2 expression that significantly attenuated clofibrate-induced HO-1 gene transcription, and siRNA knockdown of PPARα that had no effect on clofibrate-induced HO-1 promoter activity. Furthermore, deletion of the antioxidant response elements (AREs) in the HO-1 gene promoter diminished clofibrate-induced HO-1 transcription and deletion of the PPAR response elements (PPREs) had no such effect. Likewise, application of PPARα antagonists had no effect on clofibrate-induced HO-1 expression. CONCLUSION: Clofibrate induces HO-1 gene expression in cancer cells through a PPARα-independent mechanism and the Nrf2 signaling pathway is indispensible for this induction.

Efficacy and Safety Analysis of Immune Checkpoint Inhibitors plus Angiogenesis Inhibitors for the Treatment of Advanced Driver-negative NSCLC in Elderly Patients: A Retrospective Study.

Background and Objective: Immune checkpoint inhibitors (ICIs) combined with angiogenesis inhibitors may have synergistic effects in elderly patients with advanced driver-negative NSCLC, but its true efficacy remains unclear. In addition, chemotherapy tolerance in elderly NSCLC patients is poor, and the precise identification of the population that may benefit from ICIs combined with angiogenesis inhibitors is also the focus of current research. Methods: We retrospectively compared the efficacy and safety of ICIs combined with or without antiangiogenic agents in elderly patients with advanced driver-gene negative NSCLC ≥65 years of age in the Cancer Center of Suzhou Hospital Affiliated to Nanjing Medical University. The primary endpoint was PFS. Secondary endpoints were OS, ORR, and immune-related adverse events (irAEs). Results: A total of 36 patients in the IA group (immune checkpoint inhibitors plus angiogenesis inhibitors group) and 43 patients in the NIA group (immune checkpoint inhibitors without angiogenesis inhibitors group) were enrolled in the study between January 1, 2019 and December 31, 2021. The median follow-up time for patients in the IA group and NIA group was 18.2 months (95%CI: 14 - 22.5 months) and 21.4 months (95%CI: 16.7 -26.1 months), respectively. The median PFS and median OS were longer in the IA group compared to the NIA group (8.1 months vs 5.3 months; HR for PFS: 0.778, 95%CI: 0.474-1.276, P=0.32; NA vs 30.9 months; HR for OS: 0.795, 95%CI: 0.396-1.595, P=0.519). There were no significant differences in median PFS and median OS between the two groups. Subgroup analysis showed that patients in the IA group had significantly longer PFS in the subgroup with PD-L1 expression ≥50% (P=0.017), and the association between different groups and disease progression was still different in the two subgroups (P for interaction = 0.002). There was no significant difference in ORR between the two groups (23.3% vs 30.5%, P=0.465). The incidence of irAEs in the IA group was lower than that in the NIA group (39.5% vs 19.4%, P=0.05), and the cumulative incidence of treatment interruptions due to irAEs was significantly reduced (P=0.045). Conclusion: In elderly patients with advanced driver-negative NSCLC, the addition of antiangiogenic agents to ICIs therapy did not provide significant clinical benefit, but the incidence of irAEs and treatment interruptions due to irAEs was significantly reduced. In the subgroup analysis, we found that the clinical benefit of this combination therapy was observed in patients with PD-L1 expression ≥50%, which warrants further exploration.

Improving the registration stability of cone-beam computed tomography with the Sphere-Mask Optical Positioning System: a feasibility study.

Background: Cone-beam computed tomography (CBCT) is an important tool for patient positioning in radiotherapy due to its outstanding advantages. However, the CBCT registration shows errors due to the limitations of the automatic registration algorithm and the nonuniqueness of manual verification results. The purpose of this study was to verify the feasibility of using the Sphere-Mask Optical Positioning System (S-M_OPS) to improve the registration stability of CBCT through clinical trials. Methods: From November 2021 to February 2022, 28 patients who received intensity-modulated radiotherapy and site verification with CBCT were included in this study. S-M_OPS was used as an independent third-party system to supervise the CBCT registration result in real time. The supervision error was calculated based on the CBCT registration result and using the S-M_OPS registration result as the standard. For the head and neck, patients with a supervision error ≥3 or ≤-3 mm in 1 direction were selected. For the thorax, abdomen, pelvis, or other body parts, patients with a supervision error ≥5 or ≤-5 mm in 1 direction were selected. Then, re-registration was performed for all patients (selected and unselected). The registration errors of CBCT and S-M_OPS were calculated based on the re-registration results as the standard. Results: For selected patients with large supervision errors, CBCT registration errors (mean ± standard deviation) in the latitudinal (LAT; left/right), vertical (VRT; superior/inferior), and longitudinal (LNG; anterior/posterior) directions were 0.90±3.20, -1.70±0.98, and 7.30±2.14 mm, respectively. The S-M_OPS registration errors were 0.40±0.14, 0.32±0.66, and 0.24±1.12 mm in the LAT, VRT, and LNG directions, respectively. For all patients, CBCT registration errors in the LAT, VRT, and LNG directions were 0.39±2.69, -0.82±1.47, and 2.39±2.93 mm, respectively. The S-M_OPS registration errors were -0.25±1.33, 0.55±1.27, and 0.36±1.34 mm for all patients in the LAT, VRT, and LNG directions, respectively. Conclusions: This study shows that S-M_OPS registration offers comparable accuracy to CBCT for daily registration. S-M_OPS, as an independent third-party tool, can prevent large errors in CBCT registration, thereby improving the accuracy and stability of CBCT registration.