A senescence-related lncRNA signature predicts prognosis and reflects immune landscape in HNSCC.

OBJECTIVE: Long noncoding RNAs (lncRNAs) regulate cancer cell senescence in many cancers. However, their specific involvement in head and neck squamous cell carcinoma (HNSCC) remains unclear. We are looking for an ingenious prognostic signature that utilizes senescence-related lncRNAs (SRlncRNAs) to predict prognosis and provide insights into the immune landscape in HNSCC. MATERIALS AND METHODS: HNSCC clinical and Cellular senescence genes information were collected from The Cancer Genome Atlas and Human Aging Genomic Resources. Then we performed Cox and Lasso regression to locate SRlncRNAs related to the prognosis of HNSCC and built a predictive signature. Further, prognosis assessment, potential mechanisms, and immune status were assessed by Kaplan-Meier analysis, Gene Set Enrichment Analysis (GSEA), and CIBERSORT, respectively. RESULTS: A prognosis prediction model based on sixteen SRlncRNAs was identified and internally validated. Then, patients with high-risk scores suffered an unfavorable overall survival (All p < 0.05). The risk score, age, and stage were independent prognostic parameters (all p < 0.001). Our model has good predictive ability (The AUC (area under the curves) 1-year = 0.707, AUC3-year = 0.748 and AUC5-year = 0.779). Subsequently, GESA revealed SRlncRNAs regulated immune responses. Patients in the high-risk group had higher tumor mutation burden and Tumor Immune Dysfunction and Exclusion but lower levels of 37 immune checkpoint genes, immune scores, and immune cells like CD8 + T cells, follicular helper T cells, and regulatory T cells. CONCLUSIONS: A prognostic model based on SRlncRNAs is the potential target for improving immunotherapy outcomes for HNSCC.

SETD2 variation correlates with tumor mutational burden and MSI along with improved response to immunotherapy.

BACKGROUND: SETD2 protects against genomic instability via maintenance of homologous recombination repair (HRR) and mismatch repair (MMR) in neoplastic cells. However, it remains unclear whether SETD2 dysfunction is a complementary or independent factor to microsatellite instability-high (MSI-H) and tumor mutational burden-high (TMB-H) for immunocheckpoint inhibitor (ICI) treatment, and little is known regarding whether this type of dysfunction acts differently in various types of cancer. METHODS: This cohort study used multidimensional genomic data of 6726 sequencing samples from our cooperative and non-public GenePlus institute from April 1 through April 10, 2020. MSIsensor score, HRD score, RNAseq, mutational data, and corresponding clinical data were obtained from the TCGA and MSKCC cohort for seven solid tumor types. RESULTS: A total of 1021 genes underwent target panel sequencing reveal that SETD2 mutations were associated with a higher TMB. SETD2 deleterious mutation dysfunction affected ICI treatment prognosis independently of TMB-H (p < 0.01) and had a lower death hazard than TMB-H in pancancer patients (0.511 vs 0.757). Significantly higher MSI and lower homologous recombination deficiency were observed in the SETD2 deleterious mutation group. Improved survival rate was found in the MSKCC-IO cohort (P < 0.0001) and was further confirmed in our Chinese cohort. CONCLUSION: We found that SETD2 dysfunction affects ICI treatment prognosis independently of TMB-H and has a lower death hazard than TMB-H in pancancer patients. Therefore, SETD2 has the potential to serve as a candidate biomarker for ICI treatment. Additionally, SETD2 should be considered when dMMR is detected by immunohistochemistry.

An Immunogenic Cell Death-Related Gene Signature Reflects Immune Landscape and Predicts Prognosis in Melanoma Independently of BRAF V600E Status.

Immunogenic cell death (ICD) is a type of regulated cell death that can activate adaptive immune response, and its ability to reshape the tumor microenvironment via multiple mechanisms may contribute to immunotherapy. The treatment options for patients with skin cutaneous melanoma (SKCM) vary based on BRAF V600E statuses. However, all standard treatments include immunotherapy. Therefore, it is critical to identify ICD-associated signatures that can help classify patients according to benefits from ICD immunotherapy. In this study, data on melanoma samples with BRAF V600E mutation (BRAF V600E-mutant melanoma) and melanoma samples with wild-type BRAF V600E alleles (BRAF V600E WT melanoma) were collected from The Cancer Genome Atlas (TCGA) database. The ICD-related (ICD-high and ICD-low) subgroups of patients with BRAF V600E WT melanoma were established via consensus clustering. The analyses of survival, differentially expressed genes (DEGs), functional annotation, and immune landscape were performed in these two subgroups. Results showed that ICD-high subgroup was correlated with a positive overall survival (OS) and active tumor immune landscape. A model comprising seven prognosis ICD-related gene biomarkers was developed. Survival analysis and receiver operating characteristic (ROC) curve evaluation in both cohorts with BRAF V600E WT and BRAF V600E-mutant melanoma showed an accurate prognostic estimation of ICD-related risk signature. There was a correlation between immune cell infiltration and immunotherapy response and risk score. Thus, the ICD risk signature was closely associated with the tumor's immune microenvironment. Our results may provide insights to further individualize and improve precision therapeutic decision-making in BRAF V600E-mutant and WT melanoma.

FAM3D as a Prognostic Indicator of Head and Neck Squamous Cell Carcinoma Is Associated with Immune Infiltration.

Background: Globally, head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor with high morbidity and mortality. Hence, it is important to find effective biomarkers for the diagnosis and prediction of the prognosis of patients with HNSCC. FAM3D had been proven to be vital in other cancers. However, its predictive and therapeutic value in HNSCC is unclear. Therefore, it is valuable to explore the association between the expression level of FAM3D and its impacts on the prognosis and tumor microenvironment in HNSCC. Methods: The Cancer Genome Atlas (TCGA) dataset, Genotype-Tissue Expression (GTEx) dataset, the Clinical Proteomic Tumor Analysis Consortium (CPTAC) dataset, and The Human Protein Atlas (THPA) website were used to assess HNSCC expressions in tumor and nontumor tissues. Then, we further conducted immunohistochemistry experiment as internal cohort to validate the same results. The Cox regression analysis, Kaplan-Meier analysis, and nomograms were performed to find the predictive prognostic value of FAM3D in HNSCC patients and its relationship with the clinicopathological features in HNSCC. The Gene Expression Omnibus (GEO) dataset was utilized to externally verify the prognosis value of FAM3D in HNSCC. Gene Set Enrichment Analysis (GESA) was applied to search the molecular and biological functions of FAM3D. The association between FAM3D and immune cell infiltration was investigated with the Tumor Immune Estimating Resource, version 2 (TIMER2). The relationships between FAM3D expression and tumor microenvironment (TME) scores, immune checkpoints, and antitumor compound half-maximal inhibitory concentration predictions were also explored. Results: In different datasets, FAM3D mRNA and protein levels were all significantly lower in HNSCC tissues than in normal tissues, and they were strongly inversely associated with tumor grade, stage, lymph node metastasis, and T stage. Patients with high-FAM3D-expression displayed better prognosis than those with low-FAM3D-expression. FAM3D was also determined to be a suitable biomarker for predicting the prognosis of patients with HNSCC. This was externally validated in the GEO dataset. As for gene and protein level, the functional and pathway research results of FAM3D indicated that it was enriched in alteration of immune-related pathways in HNSCC. The low-expression group had higher stromal and ESTIMATE scores by convention than the high-expression group. FAM3D expression were found to be positively correlated with immune infiltrating cells, such as cancer-associated fibroblasts, myeloid-derived suppressor cells, macrophage cells, T cell CD8+ cells, regulatory T cells, and T cell follicular helper cells. FAM3D's relationships with immune checkpoints and sensitivity to antitumor drugs were also investigated. Conclusion: Our study explored the impact of FAM3D as a favorable prognostic marker for HNSCC on the tumor immune microenvironment from multiple perspectives. The results may provide new insights into HNSCC-targeted immunotherapy.

An EGFR L858R mutation identified in 1862 Chinese NSCLC patients can be a promising neoantigen vaccine therapeutic strategy.

Background: This study aimed to develop a vaccine that targets mutation-derived neoantigen in Chinese non-small-cell lung cancer (NSCLC). Methods: A cohort of 1862 Chinese NSCLC patients who underwent targeted sequencing with a 1021-gene panel was investigated. HLA typing was done using OptiType v1.0 and neoantigens were predicted by netMHCpan v4.0. HLA LOH was inferred using the lohhla algorithm and TMB were quantified by counting the total number of non-synonymous ones based on our panel data. CIBERSORT was utilized to estimate the TME in different EGFR mutant subtype by using TCGA data. Results: HLA-A*11:01(42.59%) was the top one allele and HLA-A*33:03(12.94%) ranked 12th. EGFR L858R (22.61%) was the most prevalent gene variant. The binding affinity (IC50 MT = 22.9 nM) and shared frequency (2.93%) of EGFR L858R in combination with HLA-A*33:03 were optimal. In a subsequent further analysis on immunological features of EGFR mutant subtypes, 63.1% HLA loss of heterozygosity LOH (HLA LOH) and 0.37% (7 of 1862) B2M aberrations were found in our population, both had no significant association with EGFR mutant subtypes suggesting that the process of antigen presentation involved HLA LOH and B2M mechanisms in EGFR L858R is working. Tumor mutation burden (TMB) was investigated by utilizing our panel and showed that EGFR L858R had the lowest TMB compared with other EGFR mutant subtypes. In addition, analysis of 22 immune cell types from The Cancer Genome Atlas (TCGA) data showed EGFR L858R was correlated with low level of CD8 T cells, activated CD4 memory T cells and elevated level of macrophage M2 suggesting an inhibited tumor microenvironment (TME). Conclusion: Our study identified that EGFR L858R neoantigen had the potential to generate cancer vaccines in NSCLC patients with HLA A*33:03. The neoantigen-based vaccines may become an effective salvage regimen for EGFR L858R subgroup after targeted therapy or immune checkpoint inhibitors (ICIs) failure.

CCND1 Amplification Profiling Identifies a Subtype of Melanoma Associated With Poor Survival and an Immunosuppressive Tumor Microenvironment.

Background: Although melanoma is generally regarded as an immunogenic cancer that will respond to immune checkpoint inhibitors (ICIs), melanomas with CCND1 amplification respond poorly to these therapies. Further understanding how CCND1 amplification impacts the effectiveness of ICI therapy is important for the design of future clinical trials. Methods: We used data from tumor samples taken from Chinese patients with melanoma analyzed at the Geneplus Institute (n=302), as well as data from the Cancer Genome Atlas (TCGA) database (n=367) and the Memorial Sloan Kettering Cancer Center (MSKCC) database (n=350) to estimate the prevalence of CCND1 amplification in melanoma, interrogate the relationship between CCND1 amplification and survival in patients with melanoma, and explore the molecular mechanisms of CCND1 amplification. We also established a murine model of melanoma harboring CCND1 amplification and utilized RNA-seq to verify the findings from human tissue samples. Results: Data from all three sources revealed a low frequency of CCND1 amplification co-occurring with BRAF V600, NRAS, NF1, and KIT mutations. Data from TCGA did not show a statistically significant correlation between CCND1 amplification and prognosis, irrespective of ICI use. In contrast, the MSKCC cohort showed that CCND1 amplification was an unfavorable prognostic factor for patients with melanoma, especially for patients who received ICIs and had a high tumor mutation burden (TMB). The TCGA data showed that CCND1 amplification was associated with a higher proportion of immunosuppressive cells (Treg cells and M2 macrophages) and a lower proportion of immune boosting cells (follicular helper T cells naïve B cells, CD8+ T cells). Murine models supported the association between a suppressive immune microenvironment and CCND1 amplification; tumors with CCND1 amplification had reduced mRNA expression of CD8, Gzm, B2m and Tap1, significantly higher proportions of resting CD4 memory T cells and significantly lower proportions of plasma cells, CD8 T cells, and T follicular helper cells. Furthermore, a Gene Set Enrichment Analysis (GSEA) analysis of data from the TCGA database suggested that signaling pathways involved in oxidative phosphorylation, reactive oxygen species, adipogenesis, fatty acid metabolism, DNA repair, and Myc targets were differentially enriched in melanoma tumors with CCND1 amplification. Finally, we observed a notable reduction in levels of angiogenesis-related molecules (encoded by HIF1A, VEGFA, VEGFR1, FGF2, FGFR1, FGFR4, HGF, PDGFA, PDGFRA, ANGPT1, and ANGPT2) in a high CCND1 amplification group from the TCGA database. Conclusions: Melanoma with CCND1 amplification is an independent genomic subtype associated with a poor prognosis, an immunosuppressive TME, activated oxidative and lipid metabolism, and down-regulated angiogenesis. Therefore, avoiding ICIs and antiangiogenic agents, while employing CDK4/6 inhibitors alone or in combination with ICIs, and targeting oxidative and lipid metabolism pathways, may be effective therapeutic strategies for melanoma patients harboring CCND1 amplification.

Comparison of cognitive impairments with lipid profiles and inflammatory biomarkers in unipolar and bipolar depression.

Cognitive impairments is one of important accompanied symptom in Unipolar depressive disorder (UD) and bipolar disorder (BD) that was hard to distinguish, as their diagnosis is based on behavioural observations and subjective symptoms. In this study, we could highlight the difference of cognitive ability in UD and BD by testing lipid profiles and inflammatory biomarkers in major depressive episodes (MDE). 207 subjects (96 unipolar and 111 bipolar depressed patients) were included in this study. We applied Montreal Cognitive Assessment (MoCA) to test cognitive ability. The 24-item Hamilton Depression Rating Scale was used for assessment at the beginning of treatment. A series of clinical variables and lipid profiles were collected from clinic record. We detected pro-inflammatory biomarkers Interleukin-1ß (IL-1ß), Interleukin-6 (IL-6), C-reaction protein (CRP) levels and brain-derived neurotrophic factor (BDNF) by enzyme linked immunosorbent assay. From the results, cognitive impairments were more popular in BD than UD, most obviously in severe cognitive impairments (MoCA score<23). And UD showed better cognitive ability than BD in MoCA, particularly in language domain. Compared lipid profiles like total cholesterol (TC), triglycerides (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA1), Apolipoprotein B (ApoB) and lipoprotein α (Lpα), we found that ApoB was higher in BD than UD that maybe a risk factor in cognition. There was no obviously difference in TC, TG, HDL-C, LDL-C, ApoA1, or Lpα. Also, we found CRP level in BD was higher than UD, and showed no significant difference in IL-1ß and IL-6 levels. Furthermore, BDNF level which was neurotrophic biomarker for cognition and mood was significantly declined in BD compared with UD. Correlation analysis showed that ApoB and CRP was negative closed associated with MoCA scores. And BDNF level was positive related with cognitive ability in MDE patients. From our results mentioned that quantitative lipid profiles and inflammatory biomarkers analysis might help to objectively identify between these disorders and up our understanding of their pathophysiology. And ApoB, CRP and BDNF could be as potential peripheral candidates in cognitive evaluation to distinguish UD and BD.

A high homologous recombination deficiency score is associated with poor survival and a non-inflamed tumor microenvironment in head and neck squamous cell carcinoma patients.

BACKGROUND: Homologous recombination deficiency (HRD) is a predictive factor in ovarian cancer, breast cancer, and prostate cancer for Poly (ADP-ribose) polymerase inhibitors (PARPi) therapy. HRD is understudied in head and neck squamous cell carcinoma (HNSCC) and the impact of HRD on prognosis and the tumor immune microenvironment is unclear. METHODS: We studies eight head and neck cancer patients in our center and compared the HRD score for each HNSCC patient in The Cancer Genome Atlas (TCGA) cohort with corresponding clinical characteristic mRNA and mutation data. RESULTS: Results indicated that the clinical stage (P = 0.016), gender (P = 0.003), clinical T stage (P < 0.001), HPV 16 (P = 0.003), pathologic T stage (P = 0.002), and lymphovascular invasion (P = 0.004) were associated with a homologous recombination deficiency high score (HRD-H) by logistic analysis. Multivariate analysis showed that HRD-H was an independent factor predicting survival with the adjustment of age, gender, clinical T stage, clinical N stage, and clinical M stage (HR 95 %CI 1.517; 1.128-2.039, P = 0.006). The proportion of tumor mutation burden-high (TMB-H) and microsatellite instability-high (MSI-H) patients in HRD-H patients are relatively low (9.97% and 0.0% respectively). A non-inflamed tumor microenvironment was also found in HRD-H patients. In our center, we found that two HRD-L HNSCC patients presented with an inflamed tumor microenvironment and had a good response to PD-1 therapy. Interestingly, the higher HRD score was 31 and was a non-responder to ICI treatment. CONCLUSIONS: HRD-H is associated with poor outcome in HNSCC patients. Those patients may benefit from PARPi treatment rather than ICIs treatment for its non-inflamed tumor microenvironment.

Role of PRKDC in cancer initiation, progression, and treatment.

The PRKDC gene encodes the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein. DNA-PKcs plays an important role in nonhomologous end joining (NHEJ) of DNA double-strand breaks (DSBs) and is also closely related to the establishment of central immune tolerance and the maintenance of chromosome stability. The occurrence and development of different types of tumors and the results of their treatment are also influenced by DNA-PKcs, and it may also predict the results of radiotherapy, chemotherapy, and therapy with immune checkpoint inhibitors (ICIs). Here, we discuss and review the structure and mechanism of action of PRKDC and DNA-PKcs and their relationship with cancer.

Preparation of a novel EGFR specific immunotoxin and its efficacy of anti-colorectal cancer in vitro and in vivo.

OBJECTIVES: Epithelial growth factor receptor (EGFR), as a malignancy marker, is overly expressed in multiple solid tumors including colorectal neoplasms, one of the most prevalent malignancies worldwide. The main objective of this study is to enhance the efficacy of anti-tumor therapy targeting EGFR by constructing a novel EGFR-specific immunotoxin (C-CUS245C) based on Cetuximab and recombinant Cucurmosin (CUS245C). METHODS: E. coli BL21 (DE3) PlysS (E. coli) was used to express CUS245C with a cysteine residue inserting to the C-terminus of Cucurmosin. Then immobilized metal ion affinity chromatography (IMAC) was used to purify CUS245C. The chemical conjugation method was used for the preparation of C-CUS245C. Then dialysis and IMAC were used to purify C-CUS245C. Western blot as well as SDS-PAGE was carried out to characterize the formation of C-CUS245C. At last the anti-colorectal cancer activity of C-CUS245C was investigated in vitro and in vivo. RESULTS: CUS245C with high purity could be obtained from the prokaryotic system. C-CUS245C was successfully constructed and highly purified. The cytotoxicity assays in vitro showed a significant proliferation inhibition of C-CUS245C on EGFR-positive cells for 120 h with IC50 values less than 0.1 pM. Besides, the anti-tumor efficacy of C-CUS245C was remarkably more potent than that of Cetuximab, CUS245C, and C + CUS245C (P < 0.001). Whereas the cytotoxicity of C-CUS245C could hardly be detected on EGFR-null cell line. Our results also showed that C-CUS245C had efficacy of anti-colorectal cancer in mouse xenograft model, indicating the therapeutic potential of C-CUS245C for the targeted therapy of colorectal neoplasms. CONCLUSIONS: C-CUS245C exhibits potent and EGFR-specific cytotoxicity. Insertional mutagenesis technique is worthy to be adopted in the preparation of immunotoxin. Immunotoxin can be highly purified through dialysis followed by IMAC.

Cigarette smoking promotes keratinocyte malignancy via generation of cancer stem-like cells.

Objectives: Cigarette smoking is involved in the pathogenesis of head and neck squamous cell carcinoma (HNSCC). However, the underlying molecular mechanisms of cigarette smoking-induced HNSCC carcinogenesis are unclear and may involve cancer stem-like cell generation. We examined the effects of cigarette smoke condensate (CSC) on the formation of cancer stem-like cells, which are rich in octamer-binding transcription factor (OCT)-4, inhibitor of differentiation 1 (ID1), nuclear factor (NF)-κB, and B lymphoma Mo-MLV insertion region 1 homolog (BMI-1). Materials and Methods: We used in vitro, in vivo, and archival human HNSCC tissue analysis to evaluate the effects of CSC on cancer stem-like cell formation. Results: We found that CSC regulated OCT-4 expression, which subsequently regulated ID1 and NF-κB, at the promoter, mRNA, and protein levels in vitro. Furthermore, OCT-4 knockdown with siRNA reduced ID1 expression. ID1 and NF-κB synergistically increased the expression of BMI-1 and stimulated keratinocyte sphere generation. In vivo, ID1 and NF-κB acted together to generate malignant xenograft tumors, which were aggressive locally and systemically metastatic. Clinical data confirmed that ID1- and NF-κB-positive patients had poor clinical outcomes and 5-year disease-free survival. Conclusion: Our data suggest that smoking cigarettes promoted cancer stem-like cell generation in the head and neck area via the OCT-4/ID1/NF-κB/BMI-1 signaling pathway.

Novel cucurmosin-based immunotoxin targeting programmed cell death 1-ligand 1 with high potency against human tumor in vitro and in vivo.

Immunotoxins are Ab-cytotoxin chimeric molecules with mighty cytotoxicity. Programmed cell death 1-ligand 1 (PD-L1), is a transmembrane protein expressed mainly in inflammatory tumor tissues and plays a pivotal role in immune escape and tumor progression. Although PD-L1 immune checkpoint therapy has been successful in some cases, many patients have not benefited enough due to primary/secondary resistance. In order to optimize the therapeutic efficacy of anti-PD-L1 mAb, we used durvalumab as the payload and CUS245C , a type I ribosome-inactivating protein isolated from Cucurbita moschata, as the toxin moiety, to construct PD-L1-specific immunotoxin (named D-CUS245C ) through the engineered cysteine residue. In vitro, D-CUS245C selectively killed PD-L1+ tumor cells. In vivo studies also showed that D-CUS245C had obvious antitumor effect on PD-L1+ human xenograft tumors in nude mice. In conclusion, in the combination of the toxin with mAb, this study developed a new immunotoxin targeting PD-L1, emphasizing a novel and promising treatment strategy and providing a valuable way to optimize cancer immunotherapy.

Recombinant cucurmosin-based immunotoxin targeting HER-2 with potent in vitro anti-cancer cytotoxicity.

Trastuzumab is a humanized monoclonal antibody against HER2 approved by FDA for breast and gastric cancer therapy. However, only a quarter of patients have the potential to benefit from it, and most of them develop resistance within therapy. The main purpose of this study is to broaden trastuzumab's therapeutic window by conjugating trastuzumab with recombinant cucurmosin to form an immunotoxin called T-CUS245C. T-CUS245C was chemically conjugated and the purification of T-CUS245C was evaluated by SDS-PAGE. SRB tests showed a remarkable cytotoxicity of T-CUS245C with IC50 values in picomolar range on HER2 positive cancer cells without significantly proliferation inhibition on HER2 negative cells (P < 0.01). Confocal microscopy verified the time-dependent internalization effects of T-CUS245C and revealed that the lethal efficacy can be increased by provoking the internalization. These results indicate the therapeutic potential of T-CUS245C for the HER-2 targeted therapy.

Combined α-programmed death-1 monoclonal antibody blockade and fractionated radiation therapy reduces tumor growth in mouse EL4 lymphoma.

The programmed death (PD) pathway is frequently present in the tumor microenvironment (TME) and suppresses tumor immunity by inhibiting the activity of tumor-infiltrating lymphocytes (TILs), particularly, CD8+ lymphocytes. PD immunotherapy involves stimulation of the immune response in the region surrounding the tumor but is insufficient to prevent tumor progression. Therefore, in this study, we examined the effects of combined PD immunotherapy with fractionated radiotherapy (RT) on antitumor immunity and tumor growth in lymphoma. The immune cell profiles of the TME, blood, and secondary lymphoid organs were determined 7 days after treatment. Four combination therapies were compared. The synergistic effects of αPD-1 mAb and fractionated RT on increased CD8+ lymphocytes in the TME, blood, and secondary lymphoid organs led to substantial tumor regression in mouse EL4 lymphoma, both locally and systemically. Fractionated RT for 4 days followed by αPD-1 mAb therapy was significantly superior to other schemes in terms of overall survival rates and curative rates in xenograft model mice. Our data indicated that substantial immune responses occurred following combination therapy with fractionated RT and αPD-1 mAb immunotherapy. Our findings provide important insights into the use of RT plus αPD-1 mAb as an efficacious combinatorial therapy.

Novel recombinant immunotoxin of EGFR specific nanobody fused with cucurmosin, construction and antitumor efficiency in vitro.

Epidermal growth factor receptor (EGFR) overexpression is related to the increased aggressiveness, metastases, and poor prognosis in various cancers. In this study, we successfully constructed a new EGFR nanobody-based immunotoxin rE/CUS containing cucurmosin (CUS), The immunotoxin was expressed by prokaryotic system and we obtained a yield of 5 mg protein per liter expression medium. The percentage of it's binding ability totumor cell lines A549, HepG2, SW116, which highly expressed EGFR was 55.6%, 79.6% and 97.1%, respectively, but SW620 was only 4.45%. rE/CUS has the ability to bind A549, HepG2, SW116 cells specifically, and the antigen binding capability was not affected because of extra part of CUS component. The rE/CUS significantly inhibited the cell viability against EGFR over expression tumor cell lines in a dose-and time-dependent manner. Moreover, rE/CUS also induced apoptosis of HepG2 and A549 mightily. Our results demonstrate that rE/CUS is a potential therapeutic strategy for treating EGFR-positive solid tumors.