Neoantigen-targeted TCR-engineered T cell immunotherapy: current advances and challenges.

Adoptive cell therapy using T cell receptor-engineered T cells (TCR-T) is a promising approach for cancer therapy with an expectation of no significant side effects. In the human body, mature T cells are armed with an incredible diversity of T cell receptors (TCRs) that theoretically react to the variety of random mutations generated by tumor cells. The outcomes, however, of current clinical trials using TCR-T cell therapies are not very successful especially involving solid tumors. The therapy still faces numerous challenges in the efficient screening of tumor-specific antigens and their cognate TCRs. In this review, we first introduce TCR structure-based antigen recognition and signaling, then describe recent advances in neoantigens and their specific TCR screening technologies, and finally summarize ongoing clinical trials of TCR-T therapies against neoantigens. More importantly, we also present the current challenges of TCR-T cell-based immunotherapies, e.g., the safety of viral vectors, the mismatch of T cell receptor, the impediment of suppressive tumor microenvironment. Finally, we highlight new insights and directions for personalized TCR-T therapy.

Overcoming chemoresistance to b-raf inhibitor in melanoma via targeted inhibition of phosphoenolpyruvate carboxykinase1 using 3-mercaptopropionic acid.

The resistance of melanoma to BRAF inhibitors remains a tough clinical challenge. In order to explore the underlying mechanism of drug resistance in melanoma, we established the resistant cell line to vemurafenib, and assessed the changes of drug-resistant cells on proliferation, apoptosis, oxidative stress and tumor stemness. Our results suggest that phosphoenolpyruvate carboxykinase1 (PCK1) is activated and inhibits the oxidative stress caused by vemurafenib in drug-resistant cells. Long term treatment of vemurafenib increases the expression of PCK1 which reduces the production of reactive oxygen species (ROS) by activating PI3K/Akt pathway. After the inhibition of PCK1 by 3-mercaptopropionic acid (3-MPA), the therapeutic sensitivity of vemurafenib is restored. In conclusion, this study disclosed that drug-resistant cells appeared to regulate their own proliferation, oxidative stress and tumor dryness by activating Akt/PCK1/ROS pathway, and shed new insights into acquiring drug resistance in melanoma.

Circular RNA circ_0020710 drives tumor progression and immune evasion by regulating the miR-370-3p/CXCL12 axis in melanoma.

BACKGROUND: Circular RNAs (circRNAs) have been reported to have critical regulatory roles in tumor biology. However, their contribution to melanoma remains largely unknown. METHODS: CircRNAs derived from oncogene CD151 were detected and verified by analyzing a large number of melanoma samples through quantitative real-time polymerase chain reaction (qRT-PCR). Melanoma cells were stably transfected with lentiviruses using circ_0020710 interference or overexpression plasmid, and then CCK-8, colony formation, wound healing, transwell invasion assays, and mouse xenograft models were employed to assess the potential role of circ_0020710. RNA immunoprecipitation, luciferase reporter assay and fluorescence in situ hybridization were used to evaluate the underlying mechanism of circ_0020710. RESULTS: Our findings indicated that circ_0020710 was generally overexpressed in melanoma tissues, and high level of circ_0020710 was positively correlated with malignant phenotype and poor prognosis of melanoma patients. Elevated circ_0020710 promoted melanoma cell proliferation, migration and invasion in vitro as well as tumor growth in vivo. Mechanistically, we found that high level of circ_0020710 could upregulate the CXCL12 expression via sponging miR-370-3p. CXCL12 downregulation could reverse the malignant behavior of melanoma cells conferred by circ_0020710 over expression. Moreover, we also found that elevated circ_0020710 was correlated with cytotoxic lymphocyte exhaustion, and a combination of AMD3100 (the CXCL12/CXCR4 axis inhibitor) and anti-PD-1 significantly attenuated tumor growth. CONCLUSIONS: Elevated circ_0020710 drives tumor progression via the miR-370-3p/CXCL12 axis, and circ_0020710 is a potential target for melanoma treatment.

Hsa-let-7b Suppresses Cell Proliferation by Targeting UHRF1 in Melanoma.

UHRF1 promotes melanoma progression by inducing cell proliferation, and is correlated with poor prognosis of melanoma patients. However, the regulation mechanism has not been fully elaborated. Here, we detected hsa-let-7b expression and its role in melanoma. Through Targetscan and miRanda predication, 30 overlapped miRNAs were found; further survival analysis revealed that hsa-let-7b was the only miRNA that affected the overall survival. Overexpressed hsa-let-7b could significantly inhibit the proliferation ability of A375 and A2058 cells, and this phenomenon was reversed after co-transfection with pLenti-UHRF1. In conclusion, hsa-let-7b regulates melanoma cells proliferation in vitro by targeting UHRF1.

Prognostic genes of melanoma identified by weighted gene co-expression network analysis and drug repositioning using a network-based method.

Melanoma is one of the most malignant types of skin cancer. However, the efficacy and utility of available drug therapies for melanoma are limited. The objective of the present study was to identify potential genes associated with melanoma progression and to explore approved therapeutic drugs that target these genes. Weighted gene co-expression network analysis was used to construct a gene co-expression network, explore the associations between genes and clinical characteristics and identify potential biomarkers. Gene expression profiles of the GSE65904 dataset were obtained from the Gene Expression Omnibus database. RNA-sequencing data and clinical information associated with melanoma obtained from The Cancer Genome Atlas were used for biomarker validation. A total of 15 modules were identified through average linkage hierarchical clustering. In the two significant modules, three network hub genes associated with melanoma prognosis were identified: C-X-C motif chemokine receptor 4 (CXCR4), interleukin 7 receptor (IL7R) and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit γ (PIK3CG). The receiver operating characteristic curve indicated that the mRNA levels of these genes exhibited excellent prognostic efficiency for primary and metastatic tumor tissues. In addition, the proximity between candidate genes associated with melanoma progression and drug targets obtained from DrugBank was calculated in the protein interaction network, and the top 15 drugs that may be suitable for treating melanoma were identified. In summary, co-expression network analysis led to the selection of CXCR4, IL7R and PIK3CG for further basic and clinical research on melanoma. Utilizing a network-based method, 15 drugs that exhibited potential for the treatment of melanoma were identified.

Elevated kindlin-2 promotes tumour progression and angiogenesis through the mTOR/VEGFA pathway in melanoma.

BACKGROUND: In our previous study, kindlin-2 promoted skin wound healing and decreased the permeability of neovascularization during angiogenesis. Herein, we explored the biological function and underlying mechanism of kindlin-2 in cutaneous melanoma. METHODS AND RESULTS: Through a series of in vitro assays, we found that high levels of kindlin-2 promoted migration and invasion of melanoma cells without influencing cell proliferation. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analyses showed that upregulated kindlin-2 promoted the cellular epithelial-mesenchymal transition (EMT). Importantly, we found that melanoma cells overexpressing kindlin-2 promoted angiogenesis and VEGFA secretion in vitro and facilitated tumour growth and lung metastasis in vivo. To unveil the underlying mechanism, we conducted Next-generation sequencing (NGS) and differential expression analyses. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that overlapping differentially expressed genes (DEGs) were primarily enriched in the TGF-ß, mTOR and VEGF signalling pathways. Then, we confirmed that the mTOR/VEGFA pathway was activated during the process of kindlin-2-induced melanoma progression and angiogenesis. Moreover, we demonstrated that kindlin-2 was significantly overexpressed in clinical melanoma samples and that a high level of kindlin-2 predicted a poor prognosis. CONCLUSIONS: Taken together, these findings showed that kindlin-2 promotes angiogenesis and tumour progression via the mTOR/VEGFA pathway.

Downregulation of RNF128 activates Wnt/ß-catenin signaling to induce cellular EMT and stemness via CD44 and CTTN ubiquitination in melanoma.

BACKGROUND: Ring finger proteins (RNFs) were involved in carcinogenesis. Here, we aimed to explore the detailed mechanism of RNF128 in the progression of melanoma. METHODS: We reanalyzed several gene expression profiles from the Gene Expression Omnibus (GEO) database and obtained the overlapped differential expressed RNF genes. Among them, RNF128 was selected to further explore its expression, the biological significance, and the underlying molecular mechanism, as well as the clinical relevance in melanoma patients. RESULTS: RNF128 was found to be significantly downregulated in the selected datasets, which was further verified in our melanoma tissues. Moreover, RNF128 downregulation was shown to correlate with the malignant phenotype of melanoma, and further functional assays demonstrated that low levels of RNF128 promoted melanoma progression via inducing cell epithelial-mesenchymal transition (EMT) and the acquisition of stemness. Mechanistically, RNF128 interference activated the Wnt pathway via simultaneously ubiquitinating CD44/cortactin (CTTN), resulting in CD44 and c-Myc transcription, thus revealed that RNF128 participated in a positive feedback of the Wnt pathway-CD44 loop. Clinically, we found that patients expressing low RNF128 and high CD44/CTTN levels had a poor prognosis. CONCLUSION: Downregulated RNF128 activates Wnt signaling to induce cellular EMT and stemness by ubiquitinating and degrading CD44/CTTN, and RNF128 is a reliable diagnostic and prognostic biomarker, and a deeper understanding of RNF128 may contribute to the treatment of melanoma.

TRIM44 activates the AKT/mTOR signal pathway to induce melanoma progression by stabilizing TLR4.

BACKGROUND: There is growing evidence that tripartite motif-containing protein 44 (TRIM44) plays crucial role in tumor development. However, the underlying mechanism of this deubiquitinating enzyme remains unclear. METHODS: Large clinical samples were used to detect TRIM44 expression and its associations with clinicopathological features and prognosis. Gain- and loss-of-function experiments in cell lines and mouse xenograft models were performed to elucidate the function and underlying mechanisms of TRIM44 induced tumor progression. Co-immunoprecipitation (Co-IP) assays and mass spectrometric analyses were applied to verify the interacting proteins of TRIM44. RESULTS: We found that TRIM44 was commonly amplified in melanoma tissues compared with paratumoral tissues. TRIM44 expression also positively correlated with more aggressive clinicopathological features, such as Breslow depth (p = 0.025), distant metastasis (p = 0.012), and TNM stage (p = 0.002). Importantly, we found that TRIM44 was an independent indicator of prognosis for melanoma patients. Functionally, overexpression of TRIM44 facilitated cell invasion, migration, apoptosis resistance and proliferation in vitro, and promoted lung metastasis and tumorigenic ability in vivo. Importantly, high level of TRIM44 induced melanoma cell epithelial-mesenchymal transition (EMT), which is one of the most important mechanisms for the promotion of tumor metastasis. Mechanistically, high levels of TRIM44 increased the levels of p-AKT (T308) and p-mTOR (S2448), and a specific AKT inhibitor inhibited TRIM44-induced tumor progression. Co-IP assays and mass spectrometric analyses indicated that TRIM44 overexpression induces cell EMT through activating AKT/mTOR pathway via directly binding and stabilizing TOLL-like receptor 4 (TLR4), and TLR4 interference impeded TRIM44 induced tumor progression. Moreover, we demonstrated that TRIM44 is the target of miR-26b-5p, which is significantly downregulated in melanoma tissues and may be responsible for the overexpression of TRIM44. CONCLUSIONS: TRIM44, regulated by miR-26b-5p, promotes melanoma progression by stabilizing TLR4, which then activates the AKT/mTOR pathway. TRIM44 shows promise as a prognostic predictor and a therapeutic target for melanoma patients.

Bioinformatics-based analysis reveals elevated MFSD12 as a key promoter of cell proliferation and a potential therapeutic target in melanoma.

Although recent therapeutic advances based on our understanding of molecular phenomena have prolonged the survival of melanoma patients, the prognosis of melanoma remains dismal and further understanding of the underlying mechanism of melanoma progression is needed. In this study, differential expression analyses revealed that many genes, including AKT1 and CDK2, play important roles in melanoma. Functional analyses of differentially expressed genes (DEGs), obtained from the GEO (Gene Expression Omnibus) database, indicated that high proliferative and metastatic abilities are the main characteristics of melanoma and that the PI3K and MAPK pathways play essential roles in melanoma progression. Among these DEGs, major facilitator superfamily domain-containing 12 (MFSD12) was found to have significantly and specifically upregulated expression in melanoma, and elevated MFSD12 level promoted cell proliferation by promoting cell cycle progression. Mechanistically, MFSD12 upregulation was found to activate PI3K signaling, and a PI3K inhibitor reversed the increase in cell proliferation endowed by MFSD12 upregulation. Clinically, high MFSD12 expression was positively associated with shorter overall survival (OS) and disease-free survival (DFS) in melanoma patients, and MFSD12 was an independent prognostic factor for OS and DFS in melanoma patients. Therapeutically, in vivo assays further confirmed that MFSD12 interference inhibited tumor growth and lung metastasis in melanoma. In conclusion, elevated MFSD12 expression promotes melanoma cell proliferation, and MFSD12 is a valuable prognostic biomarker and promising therapeutic target in melanoma.

[The treatment of sternal wound infection by internal fixation of sternum with titanium plate after cardiac surgery].

OBJECTIVE: To investigate the internal fixation of sternum with titanium plate for the treatment of sternal wound infection after cardiac surgery. METHODS: A retrospective study of 26 patients from Jan 2009 to Dec 2011 was carried out. All the 26 cases with sternal wounds infection after cardiac surgery, were treated by internal fixation with titanium plates. RESULTS: All the patients had chronic infection, lasting for more than 3 months. 3 patients received vacuum-assisted closure treatment after complete debridement. All the wounds were covered with pectoral major muscle flap. All the wounds healed completely with no recurrence of infection. CONCLUSIONS: Internal fixation of sternum with titanium plate can increase the stability. It helps to improve the treatment efficacy of sternal wound infection after cardiac surgery.

Plastic surgery after solid organ transplantations.

BACKGROUND: More patients receive organ transplantation surgeries due to the advancement in immunosuppressive agents and surgical techniques. Some of those patients may need to undergo plastic or reconstructive surgery. Long-term use of immunosuppressive agents raises some serious problems. Therefore, this study aimed to introduce our experience about the safety and effectiveness of plastic surgeries after solid organ allograft transplantation. METHODS: A retrospective review of 17 transplant recipients who underwent different reconstructive or cosmetic operations was carried out. The subjects included 1 heart transplant, 1 liver transplant and 15 kidney transplant recipients. RESULTS: All patients tolerated the plastic surgery procedures well. Flaps and skin grafts were the main constructive methods. There were no postoperative infections and wound dehiscence. Transferred flaps survived completely. Skin grafts took well. Three of the cosmetic surgery patients were satisfied with the results. CONCLUSIONS: Immunosuppressed organ transplant recipients can successfully undergo major reconstructive and cosmetic surgery when given special attention.

[Vertical reduction mammaplasty with wide superior pedicle].

OBJECTIVE: To report the reduction mammaplasty with vertical incision and superior wide pedicle. METHODS: Typical Lejour mosque-dome design was performed. The inferior part of glandular tissue and skin were excised. The nipple-and-areola complex (NAC) was elevated to normal position with superior wide pedicle. The breast morphology was modified with vertical scar left. RESULTS: 46 patients were treated. 4 patients had unilateral breast reduction. 14 breasts had wound dehiscence. 3 breasts received debridement, others were treated conservatively with dressings. No complete NAC necrosis occurred. CONCLUSIONS: The reduction mammaplasty with vertical incision and superior wide pedicle is a safe and effective method with a low risk of NAC necrosis.

[The study on donor site sequelae after autologous breast reconstruction with an extended latissimus dorsi flap].

OBJECTIVE: To study the prevention and treatment on the donor site sequelae after autologous breast reconstruction with extended latissimus dorsi flap. METHODS: 88 patients received breast reconstruction with extended latissimus dorsi flap between May 1999 and Nov 2004 were concerned. We analyzed the donor site sequelae by objective and subjective evaluation and we assessed the functional condition. Results Dorsal hematoma developed in 1 patient. There are 7 patients with dorsal seromas and 2 of them developed capsules; 5 patients with mild skin exfoliate and 1 patient with dry skin necrosis, 2 winged shoulders. No infection and no hypertrophic scars appeared in donor site. There is no significant functional limitation and no influence in daily life. CONCLUSIONS: The main complication after autologous breast reconstruction with extended latissimus dorsi flap was seromas and it can be controlled to decrease. There is no severe complication. It's a worthy method in autologous breast reconstruction in oriental people.

[Vertical reduction mammaplasty].

OBJECTIVE: The inverted "T" operation is a typical and classic method for breast hypertrophy. Although having good results, it leaves significant scar and tends to have bottom-out deformity with time. The purpose of this study is to introduce our experience in vertical mammaplasty. METHODS: The typical Lejour's design was used. The lower part of the breast was excised. The nipple-alveolar complex was elevated to a proper position with the superior dermal-glandular pedicle. Only vertical scar was left after the skin was closed. RESULTS: 24 patients were treated using this method. The results were satisfactory except unilateral nipple-alveolar complex necrosis occurred in one patient. Another patient had a minor revision for the dog-ear 6 months after breast reduction. CONCLUSIONS: Vertical reduction mammaplasty is effective with reduced scar and highly satisfactory results. It deserves recommendation.

[Flap transplantation combined with liposuction to treat upper limb lymphedema after mastectomy].

OBJECTIVE: To investigate a new surgical method to treat unilateral limb lymphedem after radical mastectomy. METHODS: 10 cases of upper limb lymphedema after radical mastectomy were treated using flap transfer (the lateral thoracic skin flap or latissimus dorsi musculocutaneous flap combined with liposuction). RESULTS: After the treatment, the upper limb perimeter reduced in varied degrees. Nuclear lymphatic radiography showed notable changes in lymphatic circulation. The effective results were steady during the follow-up of 3-18 months. CONCLUSION: Flap transplantation combined with liposuction is a useful treatment for limb lymphedema from radical mastectomy.