Current Status in Rechallenge of Immunotherapy.

The treatment of malignant tumors has entered the era of immunotherapy, and immune checkpoint inhibitors (ICIs) have brought significant benefits to patients. However, some patients are required to discontinue treatment with ICIs owing to factors such as disease progression and intolerable side effects. Faced with limited subsequent treatment options and complex medical needs, we searched PubMed, Embase, Cochrane library, and the NIH clinical trials database and found that ICI rechallenge could be a relevant clinical strategy. The factors that could affect the rechallenge efficacy include the patients' characteristics, therapeutic strategy selection, and the timing of treatment. Multiple factors are used to identify target population, of which clinical features and PD-L1 expression are more potential. Both single ICI rechallenge and combination therapy may have survival benefits. Patients who have tolerated initial immunotherapy well could undergo ICI rechallenge, while patients who have experienced grade 3 or higher immune-related adverse events should be carefully assessed prior to rechallenge. Interventions and the interval between two courses of ICI will clearly have an impact on the efficacy of subsequent treatment. Preliminary data evaluation supports further investigation on ICI rechallenge to identify the factors that could contribute to its efficacy.

[The Extract from Punica Granatum (Pomegranate) Leaves Promotes Apoptosis and Impairs Metastasis in Prostate Cancer Cells].

OBJECTIVE: To investigate the effects of pomegranate leaves extract(PLE)on proliferation,apoptosis and metastasis of prostate cancer cells. METHODS: The proliferation of TRAMP-C1,DU145,PC3 prostate cancer cells treated with different concentrations of PLE (final mass concentrations were 12.5,25,50,100, 200 µg/mL,respectively) for different time (24,48,72 h) was detected by MTT assay. Colony formation assay was performed to verify the long-term effects of PLE on the proliferation of DU145 and PC3 cells.After being treated with PLE for 48 h,Hoechst-33258 staining was used to observe the changes in the nucleus,the cell apoptotic rate was detected by flow cytometry,and wound-healing migration assay was perform to test the change of migration. RESULTS: In comparison with the control group,PLE in the range of 12.5-200 µg/mL had a certain inhibitory effect on the proliferation of TRAMP-C1,DU145 and PC3 cells ( P<0.05).In the range of 6.25-100 µg/mL,the number of colony formation of DU145 and PC3 was significantly reduced( P<0.01).After PLE treated for 48 h, the apoptotic features of nuclear fragmentation and the formation apoptotic body was observed in PC3. With the increase of concentration,the apoptotic rate increased gradually ( P<0.05),and the ability of cells to migrate to the scratch area was significantly weaker than the control group ( P<0.01). CONCLUSION: PLE has effect on proliferation,apoptosis and metastasis of prostate cancer cells.

Betulinic acid impairs metastasis and reduces immunosuppressive cells in breast cancer models.

Breast cancer is the most common female cancer with considerable metastatic potential, explaining the need for new candidates that inhibit tumor metastasis. In our study, betulinic acid (BA), a kind of pentacyclic triterpenoid compound derived from birch trees, was evaluated for its anti-metastasis activity in vitro and in vivo. BA decreased the viability of three breast cancer cell lines and markedly impaired cell migration and invasion. In addition, BA could inhibit the activation of stat3 and FAK which resulted in a reduction of matrix metalloproteinases (MMPs), and increase of the MMPs inhibitor (TIMP-2) expression. Moreover, in our animal experiment, intraperitoneal administration of 10 mg/kg/day BA suppressed 4T1 tumor growth and blocked formation of pulmonary metastases without obvious side effects. Furthermore, histological and immunohistochemical analyses showed a decrease in MMP-9 positive cells, MMP-2 positive cells and Ki-67 positive cells and an increase in cleaved caspase-3 positive cells upon BA administration. Notably, BA reduced the number of myeloid-derived suppressor cells (MDSCs) in the lungs and tumors. Interestingly, in our caudal vein model, BA also obviously suppressed 4T1 tumor pulmonary metastases. These findings suggested that BA might be a potential agent for inhibiting the growth and metastasis of breast cancer.