Discovery of a novel small molecule as CD47/SIRPα and PD-1/PD-L1 dual inhibitor for cancer immunotherapy.

BACKGROUND: Targeting the tumor microenvironment (TME) has emerged as a promising strategy in cancer treatment, particularly through the utilization of immune checkpoint blockade (ICB) agents such as PD-1/PD-L1 inhibitors. Despite partial success, the presence of tumor-associated macrophages (TAMs) contributes to an immunosuppressive TME that fosters tumor progression, and diminishes the therapeutic efficacy of ICB. Blockade of the CD47/SIRPα pathway has proven to be an effective intervention, that restores macrophage phagocytosis and yields substantial antitumor effects, especially when combined with PD-1/PD-L1 blockade. Therefore, the identification of small molecules capable of simultaneously blocking CD47/SIRPα and PD-1/PD-L1 interactions has remained imperative. METHODS: SMC18, a small molecule with the capacity of targeting both SIRPα and PD-L1 was obtained using MST. The efficiency of SMC18 in interrupting CD47/SIRPα and PD-1/PD-L1 interactions was tested by the blocking assay. The function of SMC18 in enhancing the activity of macrophages and T cells was tested using phagocytosis assay and co-culture assay. The antitumor effects and mechanisms of SMC18 were investigated in the MC38-bearing mouse model. RESULTS: SMC18, a small molecule that dual-targets both SIRPα and PD-L1 protein, was identified. SMC18 effectively blocked CD47/SIRPα interaction, thereby restoring macrophage phagocytosis, and disrupted PD-1/PD-L1 interactions, thus activating Jurkat cells, as evidenced by increased secretion of IL-2. SMC18 demonstrated substantial inhibition of MC38 tumor growths through promoting the infiltration of CD8+ T and M1-type macrophages into tumor sites, while also priming the function of CD8+ T cells and macrophages. Moreover, SMC18 in combination with radiotherapy (RT) further improved the therapeutic efficacy. CONCLUSION: Our findings suggested that the small molecule compound SMC18, which dual-targets the CD47/SIRPα and PD-1/PD-L1 pathways, could be a candidate for promoting macrophage- and T-cell-mediated phagocytosis and immune responses in cancer immunotherapy.

Is radical radiotherapy with/without surgery an effective treatment in the lymphoepithelial carcinoma of the salivary gland？.

BACKGROUND: There is limited information of radical radiotherapy (RT) on lymphoepithelial carcinoma of salivary gland (LECSG) regarding to the rarity of the disease. We conducted this retrospective study that evaluated the feasibility and efficacy of radical RT with/without surgery in LECSG. METHODS: We retrospectively reviewed patients that were pathologically diagnosed of LECSG and had definite or suspicious residual disease. The prescribed dose given to P-GTV and/or P-GTV-LN was 66 to 70.4 Gy. The clinical target volume (CTV) involved ipsilateral salivary gland and corresponding lymph node drainage area. RESULTS: A total of 56 patients were included. With a median follow-up of 60 months (range: 8 to 151 months), the 1-, 5-, and 10-year progression-free survival (PFS) rates were 94.6%, 84.7% and 84.7%; locoregional progression-free survival (LRPFS) rates were 98.2%, 87.4% and 87.4%; distance metastasis-free survival (DMFS) rates were 94.6%, 86.7% and 86.7%; and overall survival (OS) rates were 98.2%, 92.4% and 89.0%, respectively. A total of 7 patients without surgery were included. All patients were alive and only one patient experienced failure of distant metastasis four months after RT. The results of univariate analysis showed that compared with N stage, the number of positive lymph nodes (2 positive lymph nodes) was better prognostic predictor especially in PFS. There were no treatment-related deaths and most toxicities of RT were mild. CONCLUSIONS: Radical RT with/without surgery in LECSG for definite or suspicious residual disease is feasibility and efficacy. Most toxicities of RT were mild due to the target volume involved ipsilateral area.

Long-term outcomes of nasopharyngeal carcinoma patients with T1-2 stage in intensity-modulated radiotherapy era.

Objectives: To evaluate long-term outcomes and late toxicities of nasopharyngeal carcinoma (NPC) patients with T1-2N0-3M0 stage in intensity-modulated radiotherapy (IMRT) era. Materials and Methods: From June 2005 to October 2013, 276 patients confirmed T1-2N0-3M0 NPC treated with IMRT were reviewed, with 143 (51.8%) N0-1 disease and 133 (48.2%) N2-3 disease. Among them, 76.4% received chemotherapy. The prescribed doses given to the primary tumor and lymph nodes were 66Gy in 30 fractions. Results: After a median follow-up of 103 months, the 5-year and 10-year overall survival (OS) were 90.6% and 79.2%. The 5-year and 10-year local control (LC) rate, regional control (RC) rate and distant metastasis free survival (DMFS) were 97.0% and 91.9%, 94.1% and 92.2%, 89.4% and 87.0%, respectively. The 5-year and 10-year OS, RC rate and DMFS of N0-1 compared with those of N2-3 were 98.6% vs. 82.0% and 86.8% vs. 70.9% (P=0.000), 99.3% vs. 88.3% and 99.3% vs. 84.1% (P=0.000), 97.9% vs. 80.1% and 95.7% vs. 77.5% (P=0.000). The incidence of 3-4 late toxicities were low and mainly xerostomia and hearing deficit. The rates of radiation-induced cranial nerve palsy and temporal necrosis were 2.5% and 2.5%, respectively. Eighteen patients had the second primary tumor, of whom eight were lung cancer, six were head and neck cancer, four were others. Conclusions: Satisfactory locoregional control was achieved in T1-2N0-3M0 NPC treated with IMRT. Distant metastasis was the main failure cause and N2-3 was the main adverse prognostic factor. Second primary tumor occurred 6.5% and negatively impacted OS in NPC.

Computer-aided design of PVR mutants with enhanced binding affinity to TIGIT.

BACKGROUND: TIGIT, as a novel immune checkpoint molecule involved in T cell and NK cell anergy, could induce the immune tolerance and escape through binding with its ligand PVR. Blockade of TIGIT/PVR is considered as a promising strategy in cancer immunotherapy. However, to facilitate the design of inhibitors targeting TIGIT/PVR, the structural characteristics and binding mechanism still need to be further studied. METHODS: In this study, molecular dynamics (MD) simulations and in silico mutagenesis were used to analyze the interaction between TIGIT and its ligand PVR. Then, PVR mutants were designed and their activities were determined by using TIGIT overexpressed Jurkat cells. RESULTS: The results suggested that the loops of PVR (CC' loop, C'C″ loop, and FG loop) underwent a large intra-molecular rearrangement, and more hydrogen bond crosslinking between PVR and TIGIT were formed during MD simulations. The potential residues for PVR to interact with TIGIT were identified and utilized to predict high affinity PVR mutants. Through the biological activity evaluation, four PVR mutants (PVRS72W, PVRS72R, PVRG131V and PVRS132Q) with enhanced affinity to TIGIT were discovered, which could elicit more potent inhibitory effects compared with the wild type PVR. CONCLUSIONS: The MD simulations analysis provided new insights into the TIGIT/PVR interaction model, and the identified PVR mutants (PVRS72W, PVRS72R, PVRG131V and PVRS132Q) could serve as new candidates for immunotherapy to block TIGIT/PVR. Video Abstract.

Radiotherapy in the treatment of primary or recurrent unresectable desmoid tumors of the neck.

Purpose: Desmoid tumors are locally aggressive nonmalignant soft tissue tumors, which frequently recur after therapy. The optimal treatment is still controversial because of the lack of large research. A few studies have reported the effects of other treatments in one lesion when surgery is not possible or would cause notable functional impairment. Our aim was to examine the outcome of radiotherapy (RT) in the treatment of primary or recurrent unresectable desmoid tumors of the neck. Materials: A retrospective analysis was performed on 30 patients between 1/2008 and 12/2017, with 3 primary and 27 recurrent unresectable desmoid tumors of the neck. All cases were reviewed by pathologists. Results: The median follow-up time was 50.5 months (range 2-126 months). Radiotherapy doses varied from 50 to 66 Gy (median 60 Gy, 23/30 patients) with all fraction size of 2 Gy. The objective response rate (ORR: CR or PR) to definitive RT was 56.7% (17/30 patients). On Chi-square statistic, ORR was significantly influenced by tumor size (≤5 cm versus >5 cm) (p = .046). Age (≤ 40 versus >40 years) (p = .804), gender (p = .629), and RT dose (≤60 versus >60 Gy) (p = .613) were not significantly associated with ORR. The most common acute side effects of the radiation-related complication were grade 1-2 skin toxicities. Conclusion: Radiotherapy is a valuable option in the management of primary or recurrent unresectable DTs of the neck with good local control. Multi-institutional and prospective studies are warranted to further validate our findings.

Postoperative radiotherapy in primary resectable desmoid tumors of the neck: a case-control study.

PURPOSE: Desmoid tumors (DTs) are rare soft tissue tumors, which frequently recur after surgery. The optimal treatment approach is still controversial due to lack of randomized data. The purpose of the study was to review a relative large series of DTs of the neck with emphasis on the value of postoperative radiotherapy (RT). METHODS: A total of 68 patients with DTs of the neck region with or without postoperative RT between 1/2008 and 12/2017 were included. They were individually matched for factors including age, gender, tumor size and margin status with a cohort of patients who underwent operative without postoperative RT. The event-free survival (EFS) was compared in the two groups. RESULTS: For the study, 34 patients and 34 matched control subjects were identified. The two groups did not differ in terms of age (p = 0.810), gender (p = 0.328), tumor size (p = 0.803) and margin status (p = 0.799). Patients who received surgery plus RT had a significantly higher 3­year EFS than those who received surgery alone (74.6% vs. 13.3%, P < 0.001). Factors including postoperative RT and margin status were independent factors of EFS. The values of P were <0.001 and 0.003 and the hazard ratios (95% confidence interval) were 11.929 (4.732-30.072) and 0.299 (0.133-0.671), respectively. None of the patients treated with RT developed serious complications. CONCLUSIONS: According to our results, postoperative radiotherapy is an effective treatment in desmoid tumors of the neck. Multi-institutional and prospective studies are warranted to further validate our findings.

EZH2 suppresses the nucleotide excision repair in nasopharyngeal carcinoma by silencing XPA gene.

The enhancer of zeste homolog 2 (EZH2) is involved in a number of fundamental pathological processes of cancer. However, its role in DNA repair pathway is still unclear. Here, we have identified XPA as a novel target gene of EZH2 via a DNA repair pathway PCR array. XPA plays a pivot role in nucleotide excision repair (NER). The expression of XPA was significantly increased by EZH2 specific inhibitor GSK126 or lentiviral shEZH2 in nasopharyngeal carcinoma (NPC) CNE and 8F cell lines. Chromatin immunoprecipitation assay demonstrated that EZH2 catalyzes H3K27 trimethylation at the XPA promoters. Furthermore, we validated the negative correlation of EZH2 and XPA in a NPC tissue microarray by immunohistochemistry staining. We also found that high expression of EZH2 was positively correlated with advanced T, N, and AJCC stage of NPC; and low expression of XPA was positively correlated with advanced T and N stage. In NPC cell lines, increased XPA expression by EZH2 inhibition resulted in a more rapid removal of UVC induced 6-4PP- and CPD-DNA adducts, as well as enhanced efficiency of DNA repair after UVC irradiation as detected by the Comet assay and immunofluorescence staining of γH2Ax. Consistently, increased cell clonogenic survival, decreased apoptosis, and necrosis after UVC irradiation, and increased resistance to DNA damaging agent cisplatin was also observed in EZH2 inhibited cells. These results illustrate that EZH2 may promote carcinogenesis and cancer development of NPC by transcriptional repression of XPA gene and inactivation of NER pathway. © 2016 Wiley Periodicals, Inc.

ß-Catenin is important for cancer stem cell generation and tumorigenic activity in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is one of the most common malignant tumors with poor prognosis and recurrence in South China. The hard eradication of NPC in clinic is predominantly due to cancer stem cells (CSCs). Increasing evidence revealed that the aberrant activation of Wnt/ß-catenin was positively correlated with the produce of CSCs. To further investigate the effect of ß-catenin on CSCs and tumorigenesis in NPC, a CNE2 cell line (pLKO.1-sh-ß-catenin-CNE2) with stably suppressed expression of ß-catenin was used in this study. The expressions of biomarkers in CSCs including c-myc, Nanog, Oct3/4, Sox2, EpCAM as well as adhesion-related proteins like E-cadherin and vimentin were analyzed by western blot analysis and immunofluorescent staining. The proliferation and migration abilities were investigated by MTT assay and Transwell assay, respectively. Cell cycle was analyzed by flow cytometry. Finally, xenograft was performed to determine the effect of ß-catenin on oncogenesis in vivo. Results showed that the expressions of c-myc, Nanog, Oct3/4, Sox2, and EpCAM were all decreased in pLKO.1-sh-ß-catenin-CNE2 cells. It was also found that vimentin was downregulated, while E-cadherin was upregulated. Results of MTT and Transwell assays suggested that the proliferation and migration abilities were impaired by silencing of ß-catenin, and more cells were arrested in G1 phase when compared with the control. In vivo study indicated that the tumor growth was markedly suppressed in experimental group. Based on current findings, ß-catenin may function as an essential protein for the maintenance of migration and proliferation abilities of NPC cells, and a complicated network consisting of c-myc, Nanog, Oct3/4, Sox2, EpCAM, E-cadherin, vimentin, and ß-catenin may be involved in the inherent regulation mechanisms.

Deletion of concurrent chemotherapy on the basis of sequential chemoradiotherapy for non-metastatic stage T4 nasopharyngeal carcinoma in IMRT era.

PURPOSE: Intensity-modulated radiotherapy (IMRT) combined with concurrent chemotherapy is deemed as the mainstay treatment in locoregionally advanced nasopharyngeal carcinoma (NPC). Nevertheless, the tolerance of severe acute toxicity of concurrent chemotherapy was unsatisfied. In addition, T4 is the predicting factor of poor prognosis for NPC patients. In this retrospective analysis, the long-term outcomes IMRT combined by induction chemotherapy deleting concurrent chemotherapy with or without adjuvant chemotherapy for T4 non-metastatic NPC were analyzed. MATERIALS AND METHODS: From January 2005 to November 2016, a total of 145 biopsy-proven non-metastatic T4 NPC was treated with IMRT combined by induction chemotherapy with or without adjuvant chemotherapy. The survival and side effects of the patients were analyzed. RESULTS: Median follow-up time was 74 months (ranges, 8-186 months). 10.0%, 61.3%, 27.3%, and 1.3% developed grade 1, 2, 3, and 4 mucositis during IMRT, respectively. 5.5% and 2.0% patients experienced grade 1 and 2 nausea and vomiting; no patients developed grade 3 or 4 nausea and vomiting. Of 145 patients enrolled, 5-year and 10-year overall survival(OS) rates were 73.7% and 53.9%, local progression-free survival(LPFS) rates were 86.1% and 71.6%, regional progression-free survival(RPFS) rates were 96.7% and 92.8%, distant metastasis-free survival (DMFS) rates were 86.7%, 78.2%, respectively. At the last follow-up, five patients developed cranial nerve injury, one patient developed mandibular bone necrosis, four patients developed temporal lobe injury, four patients developed nasopharyngeal massive hemorrhage (three cases after recurrence and one case without recurrence), and five patients developed second primary tumor. CONCLUSION: The survival outcomes of treating T4 NPC IMRT combined by induction chemotherapy deleting concurrent chemotherapy with or without adjuvant chemotherapy are encouraging. Moreover, mucosal reaction, nausea, and vomiting reaction were reduced during IMRT.

Fish oil-based microemulsion can efficiently deliver oral peptide blocking PD-1/PD-L1 and simultaneously induce ferroptosis for cancer immunotherapy.

Peptide immune checkpoint inhibitors in cancer immunotherapy have attracted great attention recently, but oral delivery of these peptides remains a huge challenge due to the harsh gastrointestinal environment, large molecular size, high hydrophilic, and poor transmembrane permeability. Here, for the first time, a fish oil-based microemulsion was developed for oral delivery of programmed death-1/programmed cell death-ligand 1 (PD-1/PD-L1) blocking model peptide, OPBP-1. The delivery system was characterized, in vitro and in vivo studies were conducted to evaluate its overall implication. As a result, this nutraceutical microemulsion was easily formed without the need of co-surfactants, and it appeared light yellow, transparent, good flowability with a particle size of 152 ± 0.73 nm, with a sustained drug release manner of 56.45 ± 0.36% over 24 h and a great stability within the harsh intestinal environment. It enhanced intestinal drug uptake and transportation over human intestinal epithelial Caco-2 cells, and drastically elevated the oral peptide bioavailability of 4.1-fold higher than that of OPBP-1 solution. Meanwhile, the mechanism of these dietary droplets permeated over the intestinal enterocytic membrane was found via clathrin and caveolae-mediated endocytic pathways. From the in vivo studies, the microemulsion facilitated the infiltration of CD8+ T lymphocytes in tumors, with increased interferon-γ (IFN-γ) secretion. Thus, it manifested a promising immune anti-tumor effect and significantly inhibited the growth of murine colonic carcinoma (CT26). Furthermore, it was found that the fish oil could induce ferroptosis in tumor cells and exhibited synergistic effect with OPBP-1 for cancer immunotherapy. In conclusion, this fish oil-based formulation demonstrated great potential for oral delivery of peptides with its natural property in reactive oxygen species (ROS)-related ferroptosis of tumor cells, which provides a great platform for functional green oral delivery system in cancer immunotherapy.

Development of LAG-3/FGL1 blocking peptide and combination with radiotherapy for cancer immunotherapy.

Aside from antibodies, peptides show great potential as immune checkpoint inhibitors (ICIs) due to several advantages, such as better tumor penetration and lower cost. Lymphocyte-activation gene 3 (LAG-3) is an immune checkpoint which can induce T cell dysfunction through interaction with its soluble ligand fibrinogen like protein-1 (FGL1). Here, we found that LAG-3 expression was higher than programmed cell death protein 1 (PD-1) in multiple human cancers by TCGA databases, and successfully identified a LAG-3 binding peptide LFP-6 by phage display bio-panning, which specifically blocks the interaction of LAG-3/FGL1 but not LAG-3/MHC-II. Subsequently, d-amino acids were introduced to substitute the N- and C-terminus of LFP-6 to obtain the proteolysis-resistant peptide LFP-D1, which restores T cell function in vitro and inhibits tumor growth in vivo. Further, a bispecific peptide LFOP targeting both PD-1/PD-L1 and LAG-3/FGL1 was designed by conjugating LFP-D1 with PD-1/PD-L1 blocking peptide OPBP-1(8-12), which activates T cell with enhanced proliferation and IFN-γ production. More importantly, LFOP combined with radiotherapy significantly improve the T cell infiltration in tumor and elevate systemic antitumor immune response. In conclusion, we developed a novel peptide blocking LAG-3/FGL1 which can restore T cell function, and the bispecific peptide synergizes with radiotherapy to further enhance the antitumor immune response.

Neoadjuvant chemotherapy followed by concurrent chemoradiation for locoregionally advanced nasopharyngeal carcinoma: interim results from 2 prospective phase 2 clinical trials.

BACKGROUND: The authors studied the efficacy of neoadjuvant chemotherapy, consisting of a taxane, cisplatin, and 5-fluorouracil (5-FU) (the TPF regimen) followed by concurrent chemoradiation, in 2 separately designed and synchronously executed phase 2 trials for stage III and IVA/IVB nasopharyngeal cancer (NPC). METHODS: Patients with newly diagnosed NPC were accrued to 2 trials, 1 for patients with stage III disease and the other for patients with IVA/IVB disease. All patients received TPF (docetaxel 75 mg/m(2), cisplatin 75 mg/m(2), and 5-FU 2500 mg/m(2) every 3 weeks for 3 cycles) followed by cisplatin 40 mg/m(2) per week concurrently with either 3-dimensional conformal radiation therapy or intensity-modulated radiation therapy. RESULTS: From January 2007 to July 2011, 52 eligible patients with stage III NPC and 64 eligible patients with nonmetastatic stage IV NPC were accrued. With a median follow-up of 32.9 months, the 3-year overall survival rates were 94.8% (95% confidence interval [CI], 87.6%-100%) and 90.2% (95% CI, 81.8%-98.6%) for the stage III NPC group and the IVA/IVB NPC group, respectively. The 3-year progression-free survival, distant metastasis-free survival, and local progression-free survival rates were 78.2% (95% CI, 64.6%-91.8%), 90.5% (95% CI, 79.7%-100%), and 93.9%(87.1%-100%), respectively, for patients with stage III NPC and 85.1% (95% CI, 75.1%-95.1%), 88% (95% CI, 78.6%-97.4%), and 100%, respectively, for patients with stage IVA/IVB NPC. The most common severe (grade 3/4) hematologic and nonhematologic adverse events were neutropenia (64 patients; 55.2%) and nausea/vomiting (23 patients; 19.8%). CONCLUSIONS: Neoadjuvant TPF followed by concurrent chemoradiation was well tolerated and produced encouraging outcomes in patients with locally advanced NPC in this hypothesis-generating study. The authors concluded that randomized controlled trials are warranted to definitively confirm this aggressive and potentially efficacious strategy.

Development of a novel peptide targeting GPR81 to suppress adipocyte-mediated tumor progression.

GPR81, initially discovered in adipocytes, has been found to suppress lipolysis when activated. However, the current small molecules that target GPR81 carry the risk of off-target effects, and their impact on tumor progression remains uncertain. Here, we utilized phage display technology to screen a GPR81-targeting peptide named 7w-2 and proceeded to demonstrate its bioactivity. Although 7w-2 did not affect the proliferation of tumor cells, it effectively reduced adipocyte catabolism in vitro, consequently restraining the proliferation of co-cultured tumor cells. Furthermore, our findings revealed that 7w-2 could inhibit lipolysis in vivo, leading to a significant impediment in tumor growth and metastasis in the 4T1 murine tumor model. Additionally, 7w-2 exhibited the ability to significantly elevate the proportion and functionality of CD8+ T cells. Our study introduces 7w-2 as the first peptide targeting GPR81, shedding light on its potential role in adipocytes in suppressing tumor progression.

Design of a novel chimeric peptide via dual blockade of CD47/SIRPα and PD-1/PD-L1 for cancer immunotherapy.

Although immune checkpoint inhibition has been shown to effectively activate antitumor immunity in various tumor types, only a small subset of patients can benefit from PD-1/PD-L1 blockade. CD47 expressed on tumor cells protects them from phagocytosis through interaction with SIRPα on macrophages, while PD-L1 dampens T cell-mediated tumor killing. Therefore, dual targeting PD-L1 and CD47 may improve the efficacy of cancer immunotherapy. A chimeric peptide Pal-DMPOP was designed by conjugating the double mutation of CD47/SIRPα blocking peptide (DMP) with the truncation of PD-1/PD-L1 blocking peptide OPBP-1(8-12) and was modified by a palmitic acid tail. Pal-DMPOP can significantly enhance macrophage-mediated phagocytosis of tumor cells and activate primary T cells to secret IFN-γ in vitro. Due to its superior hydrolysis-resistant activity as well as tumor tissue and lymph node targeting properties, Pal-DMPOP elicited stronger anti-tumor potency than Pal-DMP or OPBP-1(8-12) in immune-competent MC38 tumor-bearing mice. The in vivo anti-tumor activity was further validated in the colorectal CT26 tumor model. Furthermore, Pal-DMPOP mobilized macrophage and T-cell anti-tumor responses with minimal toxicity. Overall, the first bispecific CD47/SIRPα and PD-1/PD-L1 dual-blockade chimeric peptide was designed and exhibited synergistic anti-tumor efficacy via CD8+ T cell activation and macrophage-mediated immune response. The strategy could pave the way for designing effective therapeutic agents for cancer immunotherapy.

Identification of a novel small-molecule inhibitor targeting TIM-3 for cancer immunotherapy.

PD-1/PD-L1 blockade has achieved substantial clinical results in cancer treatment. However, the expression of other immune checkpoints leads to resistance and hinders the efficacy of PD-1/PD-L1 blockade. T cell immunoglobulin and mucin domain 3 (TIM-3), a non-redundant immune checkpoint, synergizes with PD-1 to mediate T cell dysfunction in tumor microenvironment. Development of small molecules targeting TIM-3 is a promising strategy for cancer immunotherapy. Here, to identify small molecule inhibitors targeting TIM-3, the docking pocket in TIM-3 was analyzed by Molecular Operating Environment (MOE) and the Chemdiv compound database was screened. The small molecule SMI402 could bind to TIM-3 with high affinity and prevent the ligation of PtdSer, HMGB1, and CEACAM1. SMI402 reinvigorated T cell function in vitro. In the MC38-bearing mouse model, SMI402 inhibited tumor growth by increasing CD8+ T and natural killing (NK) cells infiltration at the tumor site, as well as restoring the function of CD8+ T and NK cells. In conclusions, the small molecule SMI402 shows promise as a leading compound which targets TIM-3 for cancer immunotherapy.

Identification and optimization of peptide inhibitors to block VISTA/PSGL-1 interaction for cancer immunotherapy.

Developing new therapeutic agents for cancer immunotherapy is highly demanding due to the low response ratio of PD-1/PD-L1 blockade in cancer patients. Here, we discovered that the novel immune checkpoint VISTA is highly expressed on a variety of tumor-infiltrating immune cells, especially myeloid derived suppressor cells (MDSCs) and CD8+ T cells. Then, peptide C1 with binding affinity to VISTA was developed by phage displayed bio-panning technique, and its mutant peptide VS3 was obtained by molecular docking based mutation. Peptide VS3 could bind VISTA with high affinity and block its interaction with ligand PSGL-1 under acidic condition, and elicit anti-tumor activity in vivo. The peptide DVS3-Pal was further designed by d-amino acid substitution and fatty acid modification, which exhibited strong proteolytic stability and significant anti-tumor activity through enhancing CD8+ T cell function and decreasing MDSCs infiltration. This is the first study to develop peptides to block VISTA/PSGL-1 interaction, which could act as promising candidates for cancer immunotherapy.

Second Primary Lung Adenocarcinoma After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma.

Objective: The improvement of the efficacy of intensity-modulated radiotherapy (IMRT) for nasopharyngeal cancer (NPC) has prolonged the survival of patients, and the incidence of the second tumor has gradually increased. Among them, second primary lung adenocarcinoma (SPLAC) attributes the highest incidence. This study aimed to determine the long-term risk of SPLAC in NPC patients after IMRT. Methods: From May 2005 to May 2018, a total of 1,102 non-metastatic NPC patients who received IMRT in our hospital were enrolled, and the incidence and efficacy of SPLAC were followed up in the long term. Results: Over a median follow-up period of 66 months, a total of 22 cases of SPLAC were observed, with an incidence of 2.0%. The 1-, 2-, 3-, 4-, and 5-year cumulative risks of SPLAC were 0.4%, 0.7%, 0.8%, 1.1%, and 1.7%, respectively. During follow-up, 90.9% (20/22) of the SPLAC detected was in early stage, and the recurrence rate of surgery alone was 5.3% (1/19). Conclusion: In NPC patients, the proportion of SPLAC after IMRT was similar to that of the normal population, and most of them were found in early stage during follow-up, with good surgical efficacy.

Is postoperative radiotherapy an essential treatment for nonmetastatic lymphoepithelial carcinoma of the salivary gland?

BACKGROUND: Lymphoepithelial carcinoma of salivary gland (LECSG) is a rare malignant tumor. Whether postoperative radiotherapy (PORT) can improve locoregional control and which patients can benefit from PORT are unknown. This study aimed to evaluate the role of PORT and provide individualized suggestions for postoperative therapy in patients with LECSG. PATIENTS AND METHODS: We retrospectively reviewed patients with nonmetastatic LECSG who underwent surgery with or without PORT. Recursive partitioning analysis (RPA) was performed to categorize the patients and predict progression-free survival (PFS). RESULTS: A total of 223 patients were included, 34 (15.2%) received surgery alone, whereas the remaining 189 (84.8%) underwent PORT in the initial treatment. Although patients in the PORT group were with advanced T stage and N stage, the PORT group had an advantage over the non-PORT group on 1-year, 5-year and 10-year PFS and locoregional control (LRC). PORT was an independent prognostic factor for PFS and LRC. Furthermore, compared with T stage and N stage, the size of the primary tumor and the number of positive lymph nodes were better prognostic predictors. The RPA model was generated according to the endpoint of PFS and categorized patients into 3 prognostic groups: low-risk (maximum diameter of primary lesion (≤3 cm) and number of positive lymph nodes (≤2)), intermediate-risk (maximum diameter of primary lesion (>3 cm) and number of positive lymph nodes (≤2)), and high-risk (number of positive lymph nodes (>2)), with corresponding 5-year PFS rates of 90.0%, 75.0%, and 51.0%, respectively. Significant improvement in PFS was observed in the PORT group among intermediate-risk (P = 0.000) and high-risk patients (P = 0.000). CONCLUSIONS: PORT was shown to be a positive prognostic factor for PFS and LRC of LECSG. PORT was an essential treatment especially for patients with >3 cm maximum diameter of primary lesion and/or >2 positive lymph nodes.

Long-term outcomes of induction chemotherapy followed by intensity-modulated radiotherapy and adjuvant chemotherapy in nasopharyngeal carcinoma patients with N3 disease.

OBJECTIVES: To evaluate long-term outcomes of induction chemotherapy (IC) followed by intensity-modulated radiotherapy (IMRT) and adjuvant chemotherapy (AC) in nasopharyngeal carcinoma (NPC) patients with N3 disease. MATERIALS AND METHODS: From September 2005 to August 2016, 143 patients confirmed NPC with the 8th AJCC/UICC staging criteria N3 were reviewed. All patients received IC followed by IMRT and AC. RESULTS: After a median follow-up of 67 months, the 5-year and 10-year overall survival (OS), progression-free survival (PFS), distant metastasis free survival (DMFS), local progression-free survival (LPFS) and regional progression-free survival (RPFS) were 75.7% and 61.6%, 61.2% and 53.4%, 73.1% and 72.1%, 92.4% and 87%, 88.9% and 81.8%, respectively. Multivariate analyses indicated that T stage (P = 0.001) appeared to be prognostic factors for OS. T stage (P = 0.001 and P = 0.002) and neck lymph node necrosis (P = 0.015 and P = 0.045) were independent predictors of PFS and DMFS. The acute toxicities were mainly grade 1/2 hematologic toxicities in patients treated with IC+IMRT+AC, and severe toxicities were uncommon. CONCLUSIONS: IC followed by IMRT and AC achieved satisfactory long-term survival outcomes in NPC patients with N3 disease. Neck lymph node necrosis and late T stage served as predictors of poor prognosis for patients.