[Efficacy of adjuvant programmed cell death 1 (PD-1) monoclonal antibody immunotherapy in Chinese patients with resected stage â ¡-â ¢ melanoma].

Objective: To explore the efficacy of adjuvant programmed cell death 1 (PD-1) monoclonal antibody immunotherapy in Chinese patients with resected stage Ⅱ-Ⅲ melanoma. Methods: A total of 296 patients who underwent radical surgery for stage Ⅱ-Ⅲ cutaneous orlimb melanoma at Fudan University Shanghai Cancer Center and Shanghai Electric Power Hospital between 2017 and 2021 and received adjuvant PD-1 monoclonal antibody immunotherapy, low-dose interferon (IFN), or observational follow-up were enrolled in this study. Patients were divided into the PD-1 monoclonal antibody group (164 cases) and the IFN or observation group (IFN/OBS group, 132 cases) based on postoperative adjuvant treatment methods. Patients' disease recurrence and survival were observed. Results: Among the 296 patients, 77 had cutaneous melanoma and 219 had limb melanoma; 110 were stage Ⅱ and 186 were stage Ⅲ. Among stage Ⅱ patients, the median recurrence-free survival (RFS) in the PD-1 monoclonal antibody group (46 cases) did not reach, while the median RFS in the IFN/OBS group (64 cases) was 36 months. The 1-year RFS rates were 85.3% and 92.1% and the 2-year RFS rates were 71.9% and 63.7% in the PD-1 monoclonal antibody group and the IFN/OBS group, respectively, with no statistically significant difference (P=0.394). Among stage Ⅲ patients, the median RFS rates in the PD-1 monoclonal antibody group (118 cases) and the IFN/OBS group (68 cases) were 23 and 13 months, respectively. The 1-year RFS rates were 70.0% and 51.8% and the 2-year RFS rates were 51.8% and 35.1%in the PD-1 monoclonal antibody group and the IFN/OBS group, respectively, with a statistically significant difference (P=0.010). Stratified analysis showed that the advantage of PD-1 monoclonal antibody adjuvant therapy in improving RFS persisted in the subgroups of primary ulceration (HR=0.558, 95% CI: 0.348-0.893), lymph node macroscopic metastasis (HR=0.486, 95% CI: 0.285-0.828), stage ⅢC (HR=0.389, 95% CI: 0.24-0.63), and the subgroup without BRAF/c-Kit/NRAS gene mutations (HR=0.347, 95% CI: 0.171-0.706). In terms of recurrence patterns, in stage Ⅱ patients, the recurrence and metastasis rate was 15.2% (7/46) in the PD-1 monoclonal antibody group, significantly lower than the IFN/OBS group [43.8% (28/64), P=0.002]. In stage Ⅲ melanoma patients, the recurrence and metastasis rate was 42.4% (50/118) in the PD-1 monoclonal antibody group, also lower than the IFN/OBS group [63.2% (43/68), P=0.006]. Conclusions: In real-world settings, compared with patients receiving low-dose IFN adjuvant therapy or observational follow-up, PD-1 monoclonal antibody immunotherapy can reduce the recurrence and metastasis rate of cutaneous and limb melanoma, and prolong the postoperative RFS of stage Ⅲ cutaneous and limb melanoma patients. Patients with a heavier tumor burden benefit more from immunotherapy.

Evaluation of four protein extraction methods for proteomic analysis of mango peel.

The peel of mango (Mangifera indica L.) is a special plant tissue that contains many compounds that interfere with protein extraction. A successful separation with Two-dimensional electrophoresis (2-DE) is the key step for proteomic analysis. To evaluate the efficiencies of mango peel protein extraction for 2-DE, four extraction methods were tested: 1) 2-D clean-up kit, 2) trichloroacetic acid/acetone precipitation, 3) phenol extraction, 4) phenol with methanol/ammonium acetate precipitation. The results showed that the phenol with methanol/ammonium acetate precipitation produced the best quality protein extraction and separation. Proteins were separated in 30-70 and >70 kDa ranges better than with the other methods. Acidic proteins had better resolution with fewer horizontal and vertical streaks. Sixteen proteins were identified by maxtrix-assisted laser desorption/ ionisation time-of-flight tandem mass spectrometry (MALDI-TOF/ TOF-MS/MS). The result demonstrated that each of these four methods can be used to prepare mango peel proteins. The phenol with methanol/ ammonium acetate precipitation was the best choice for proteomic analysis of mango peel.

Cytotoxicity of PM(2.5) and PM(2.5--10) ambient air pollutants assessed by the MTT and the Comet assays.

Ambient air particulate matters are classified into two distinct modes in size distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effects on human populations has long been recognized, however, the toxicology of these adverse effects has not been clarified. In the current report, the cytotoxic effects of the solvent-extractable organic compounds (SEOC) from fine particles smaller than 2.5 microm (PM(2.5)) and from coarse particles between 2.5-10 microm (PM(2.5-10)) were studied. Nine 24h consecutive monthly samples were tested to determine the correlation between cytotoxicity and total SEOC in two size fractions of particulate air pollution. Cytotoxicity of SEOC was measured by two micro-scale mammalian cells-based bioassays: the MTT cell proliferation assay, and the Comet assay for the detection of DNA damage. A well-defined mammalian cell line - Rat 6 rodent fibroblast was employed in the study. The SEOC extracts of air particulate matters were sub divided into two equal parts. One part was dissolved in DMSO, the other in KOH/hexane and then conjugated with bovine serum albumin to produce a lipid-soluble fraction for testing. The DMSO fraction would contain mainly the polycyclic aromatic hydrocarbons (PAH), alkanes and alkanols, while the lipid-soluble fraction would be enriched with fatty acids. The results from MTT assay showed that cytotoxicity of the PM(2.5) was much more severe than the PM(2.5-10), suggesting that toxic SEOC were confined to the fine particles. By and large, the DMSO solubles were much more toxic than the lipid solubles. The degree of cytotoxicity of the DMSO soluble samples is positively correlated to the amount of particulates present in the ambient air. For the PM(2.5), the winter samples were significantly more toxic than the summer samples in terms of cell killing, which seemed to be a direct reflection of the total loading of organic matter in the samples. Results from Comet assays showed that SEOC samples of PM(2.5) derived from winter months induced DNA damage at dosages resulting in no obvious cell killing in the MTT assay. Thus, long-term exposure to non-killing dosage of air pollutants may lead to the accumulation of DNA lesions, which may be one of the mechanisms responsible for the chronic adverse health effects of particulate air pollution.