In view of the great importance bestowed on amino acids as antioxidants in oxidation resistance, we attempted two common redox titration methods in this report, including micro-potassium permanganate titration and iodometric titration, to measure the antioxidative capacity of 20 amino acids, which are the construction units of proteins in living organisms. Based on the relative intensities of the antioxidative capacity, we further conducted a quantitative comparison and found out that the product of experimental values obtained from the two methods was proven to be a better indicator for evaluating the relative antioxidative capacity of amino acids. The experimental results were largely in accordance with structural analysis made on amino acids. On the whole, the 20 amino acids concerned could be divided into two categories according to their antioxidative capacity. Seven amino acids, including tryptophan, methionine, histidine, lysine, cysteine, arginine and tyrosine, were greater in total antioxidative capacity compared with the other 13 amino acids.

Bufalin, one of the active ingredients of the Chinese drug Chan su, exhibits significant antitumor activity against various cancer types. However, the role of bufalin in renal cell carcinoma (RCC) remains unclear. In the present study, it was demonstrated that bufalin inhibited cell proliferation, blocked the cell cycle in the G2/M phase, and reduced the metastasis of human RCC ACHN cells via the upregulation of p21waf/cip1 and E-cadherin and the downregulation of cyclin dependent kinase 1, cyclin B1, N-cadherin, and hypoxia-inducible factor-1α (HIF-1α). Further mechanistic study revealed that bufalin reduced the expression of phosphorylated (phospho)-Akt and phospho-mammalian target of rapamycin (mTOR). Moreover, HIF-1α expression may be regulated through the inhibition of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mTOR signaling pathway. Thus, the present results suggest that bufalin induces cell cycle arrest and suppresses metastasis; this process may be associated with the PI3K/Akt/mTOR signaling pathway. Accordingly, it is suggested that bufalin is a therapeutic agent for RCC.

Glaucocalyxin A (GLA), a major component isolated from Rabdosia japonica, has been proven to show anti-bacterial and anti-tumor biological characteristics according to previous studies. However, its potential effect on bladder cancer remains unknown. The present research aims to investigate the underlying mechanism in treating bladder cancer in vivo and in vitro. Cell proliferation was analyzed by CCK-8 assay and colony formation. Flow cytometry was used to measure the cell cycle distribution and apoptosis. The expressions of the cell cycle and apoptosis-related proteins were detected by western blotting and immunofluorescence staining. Meanwhile, the in vivo study was performed to evaluate the anti-tumor effect on a UMUC3 subcutaneous tumor of NOD/SCID mice model. GLA suppressed colony-formation ability, triggered G2/M arrest and promoted apoptosis of UMUC3 cells in a dose-dependent manner. Furthermore, western blotting showed that GLA downregulated the expressions of PI3K p85, p-Akt, Bcl-2, CDK1, Cyclin B1 whereas upregulated the levels of PTEN, Bax, Cleaved Caspase-3. In vivo, GLA at a dosage of 20 mg/kg significantly inhibited tumor growth compared with the control group by intraperitoneal injection. These results suggested that GLA-related G2/M arrest and apoptosis in UMUC3 cells were mediated by a suppressed PI3K/Akt signaling pathway, which regulated p21Waf1/Cip1 as well as intrinsic caspase cascade. Collectively, our observations could help to develop new drugs targeting the PI3K/Akt pathway for the treatment of bladder cancer.

No abstract

Programmed cell death protein 1 (PD-1) blockade is a promising therapeutic strategy against prostate cancer. Nitroxoline has been found to have effective anticancer properties in several cancer types. We investigated the efficacy of a combination therapy involving nitroxoline and PD-1 blockade in a prostate cancer mouse model. In our in vitro analysis , we found that nitroxoline inhibited the viability and proliferation of the mouse prostate cancer cell line RM9-Luc-PSA. Additionally, nitroxoline downregulated the expressions of phospho-PI3 kinase, phospho-Akt (Thr308), phospho-Akt (Ser473), phospho-GSK-3β, Bcl-2, and Bcl-xL. Nitroxoline also downregulated programmed death-ligand 1 (PD-L1) expression levels in prostate cancer cell line and tumor tissue. In our murine prostate cancer orthotopic model, nitroxoline plus PD-1 blockade synergistically suppressed tumor growth when compared with nitroxoline or PD-1 blockade alone, leading to reductions in tumor weight, bioluminescence tumor signals, and serum prostate-specific antigen levels. Furthermore, fluorescence-activated cell sorting analysis showed that the combination strategy significantly enhanced antitumor immunity by increasing CD44 + CD62L + CD8 + memory T cell numbers and reducing myeloid-derived suppressor cell numbers in peripheral blood. In conclusion, our findings suggest that nitroxoline plus PD-1 blockade may be a promising treatment strategy in patients with prostate cancer.

Chimeric antigen receptors T (CAR-T) cell therapy of cancer is a rapidly evolving field. It has been shown to be remarkably effective in cases of hematological malignancies, and its approval by the FDA has significantly increased the enthusiasm for wide clinical usage and development of novel CAR-T therapies. However, it has also challenged physicians and investigators to recognize and deal with treatment-associated toxicities. A total of 2592 patients were included from 84 eligible studies that were systematically searched and reviewed from the databases of PubMed, de, the American Society of Hematology and the Cochrane Library. The meta-analysis and subgroup analysis by a Bayesian logistic regression model were used to evaluate the incidences of therapy-related toxicities such as cytokine release syndrome (CRS) and neurological symptoms (NS), and the differences between different targets and cancer types were analyzed. The pooled all-grade CRS rate and grade ≥ 3 CRS rate was 77% and 29%, respectively, with a significantly higher incidence in the hematologic malignancies (all-grade: 81%; grade ≥ 3: 29%) than in solid tumors (all-grade: 37%; grade ≥ 3: 19%). The pooled estimate NS rate from the individual studies were 40% for all-grade and 28% for grade ≥ 3. It was also higher in the hematologic subgroup than in the solid tumors group. The subgroup analysis by cancer type showed that higher incidences of grade ≥ 3 CRS were observed in anti-CD19 CAR-T therapy for ALL and NHL, anti-BCMA CAR-T for MM, and anti-CEA CAR-T for solid tumors, which were between 24–36%, while higher incidences of grade ≥ 3 NS were mainly observed in CD19-ALL/NHL (23–37%) and BCMA-MM (12%). Importantly, subgroup analysis on anti-CD19 CAR-T studies showed that young patients (vs. adult patients), allologous T cell origin (vs. autologous origin), gamma retrovirus vector, and higher doses of CAR-T cells were associated with high-grade CRS. On the other hand, the patients with NHL (vs ALL), administered with higher dose of CAR-T, and adult patients (vs. young patients) had an increased incidence of grade ≥ 3 NS events. This study offers a comprehensive summary of treatment-related toxicity and will guide future clinical trials and therapeutic designs investigating CAR T cell therapy.

No abstract

Renal cell carcinoma (RCC) management has undergone a major transformation over the past decade; immune checkpoint inhibitors are currently undergoing clinical trials and show promising results. However, the effectiveness of immune checkpoint inhibitors in patients with metastatic RCC (mRCC) is still limited. Lycorine, an alkaloid extracted from plants of the Amaryllidaceae family, is touted as a potential anti-cancer drug because of its demonstrative growth inhibition capacity (induction of cell cycle arrest and inhibition of vasculogenic mimicry formation). Moreover, T cell checkpoint blockade therapy with antibodies targeting cytotoxic T-lymphocyte associated protein 4 (CTLA-4) has improved outcomes in cancer patients. However, the anti-tumor efficacy of combined lycorine and anti-CTLA-4 therapy remains unknown. Thus, we investigated a combination therapy of lycorine hydrochloride and anti-CTLA-4 using a murine RCC model. As a means of in vitro confirmation, we found that lycorine hydrochloride inhibited the viability of various RCC cell lines. Furthermore, luciferase-expressing Renca cells were implanted in the left kidney and the lung of BALB/c mice to develop a RCC metastatic mouse model. Lycorine hydrochloride and anti-CTLA-4 synergistically decreased tumor weight, lung metastasis, and luciferin-staining in tumor images. Importantly, the observed anti-tumor effects of this combination were dependent on significantly suppressing regulatory T cells while upregulating effector T cells; a decrease in regulatory T cells by 31.43% but an increase in effector T cells by 31.59% were observed in the combination group compared with those in the control group). We suggest that a combination of lycorine hydrochloride and anti-CTLA-4 is a viable therapeutic option for RCC patients.