Diterpenoids from Wedelia prostrata and Their Derivatives and Cytotoxic Activities.

One new ent-kaurane diterpenoid, 11ß,16α-dihydroxy-ent-kauran-19-oic acid (1), together with eight known analogues 2 - 9 were isolated from the aerial parts of Wedelia prostrata. One of the acidic diterpenoids, kaurenoic acid (3), was converted to seven derivatives, 10 - 16. All compounds were evaluated for their cytotoxic activity in vitro against human leukemia (K562), liver (HepG-2), and stomach (SGC-7901) cancer cell lines. Only four kaurenoic acid derivatives, 13 - 16, with 15-keto and substitutions at C(19) position, exhibited notable cytotoxic activities on these tumor cell lines with IC50 value ranging from 0.05 to 3.71 µm. Compounds 10 - 12, with oxime on C(15) showed moderate inhibitory effects and compounds 1 - 9 showed no cytotoxicities on them. Structure-activity relationships were also discussed based on the experimental data obtained. The known derivative, 15-oxokaurenoic acid 4-piperdin-1-ylbutyl ester (17), induced typical apoptotic cell death in colon SW480 cells upon evaluation of the apoptosis-inducing activity by flow-cytometric analysis.

Prognostic and Potential Therapeutic Roles of PRKDC Expression in Lung Cancer.

PRKDC is a key factor involved in the ligation step of the non-homologous end joining pathway. Its dysfunction has proven to be a biomarker for radiosensitivity of cancer cells. However, the prognostic value of PRKDC and its underlying mechanisms have not been clarified yet. In this study, we found that PRKDC overexpressed in lung adenocarcinoma (LUAD) and is significantly related to unfavorable survival, while downregulation of PRKDC is link to inflamed tumor immune signature. Our further in vitro results also showed a potent antitumor efficacy of PRKDC inhibitors alone or combined with cisplatin in human lung cancer cells. This study demonstrated that PRKDC is a potential prognostic biomarker, immunotherapy target, and promising combination candidate for chemotherapy for lung cancer, and highlighted the potential of PRKDC-targeted inhibitors for the treatment of lung cancer.

Prognostic and therapeutic roles of SETD2 in cutaneous melanoma.

BACKGROUND: Cutaneous melanoma (CM) is an aggressive form of skin cancer with limited treatment options for advanced stages. Prognostic markers that accurately predict patients' outcomes and guide therapeutic strategies are crucial for improving melanoma management. SETD2 (SET Domain-Containing Protein 2), a histone methyltransferase involved in chromatin remodeling and gene regulation, has recently emerged as a tumor suppressor. Its dysfunction is involved in oncogenesis in some cancers, but little is known about its functions in progression and therapeutic response of melanoma. METHODS: RNA-seq and clinical data from public database were used to evaluate the survival analysis, gene set enrichment, IC50 of therapeutics and immunotherapy response. SETD2 knock-out A375 cell line (A375SETD2ko) was developed by Crispr/cas9 and CCK-8 analysis and nude mice used to evaluate the proliferation and invasion of melanoma cells in vitro and in vivo, while Western blotting tested the MMR-related protein. RESULTS: SETD2 was commonly down-regulated in melanoma samples which demonstrated an unfavorable survival. Cells without SETD2 expression tend to have a more progressive and invasive behavior, with resistance to chemotherapy. However, they are more sensitive to tyrosine kinase inhibitors (TKIs). They also exhibit inflamed features with lower TIDE (Tumor Immune Dysfunction and Exclusion) score and higher tumor mutation burden (TMB), showing that these patients may benefit from immunotherapy. CONCLUSIONS: This study revealed that SETD2 dysfunction in melanoma implied a poor prognosis and chemotherapy resistance, but highly sensitive to TKIs and immunotherapy, highlighting the prognostic and therapeutic value of SETD2 in cutaneous melanoma.

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.

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.

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 (AU)