Background: Gynecological cancers, including cervical cancer, ovarian cancer and endometrial cancer are leading causes of cancer-related death in women worldwide. Diet plays an important role in cancer development, which is widely accepted. However, the associations between dietary intakes and gynecological cancers remain unclear. Methods: A total of 12,437 women aged over 20 years from the National Health and Nutrition Examination Survey (NHANES), conducted from 2007–2016, were included in this study. The relationships between 30 dietary factors (4 macronutrients, 15 vitamins, 9 minerals, caffeine and alcohol) and gynecological cancers were assessed. Results: We observed negative correlations of intakes of phosphorus (odds ratio (OR), 95% confidence interval (CI); 0.998 (0.996, 0.999), p = 0.002) with cervical cancer, and intakes of vitamin B12 (0.812 (0.714, 0.925), p = 0.002), phosphorus (0.997 (0.996, 0.999), p < 0.001) and alcohol (0.971 (0.950, 0.992), p = 0.009) with endometrial cancer. The data showed positive associations of intake of caffeine (1.002 (1.001, 1.003), p = 0.003) with cervical cancer, and intake of copper (2.754 (1.313, 5.778), p = 0.009) with endometrial cancer. In addition, we found potential negative correlations between intake of vitamin B1 (p = 0.025) and cervical cancer; zinc (p = 0.048) and ovarian cancer; and potassium (p = 0.032) and endometrial cancer. Potential positive associations were found between intake of calcium and cervical cancer (p = 0.026) and endometrial cancer (p = 0.034), and between sodium (p = 0.042) and endometrial cancer. Intakes of protein, total sugars, total fat, cholesterol, vitamin A, alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, vitamin B2, niacin, vitamin B6, food folate, vitamin C, vitamin D, vitamin E, vitamin K, magnesium, iron and selenium showed no relationship with gynecological cancers (p > 0.05). Conclusion: Specific dietary factors were associated with gynecological cancers. More epidemiological studies are needed to validate our results.

Hypoxia and its induced vasculogenic mimicry (VM) formation, which both closely related with stem-like side population (SP) cells, are the main culprits leading to tumor invasion and metastasis. Sinomenine exhibits excellent anticancer activity in breast cancer, but whether and how it affects hypoxia-triggered VM formation in breast cancer SP cells remains unclear. In this study, breast cancer SP cells were sorted from MDA-MB-231 cells and cultured with sinomenine under hypoxic conditions. Sinomenine obviously repressed the migration and VM formation of breast cancer SP cells. Through downregulating SIAH2 and HIF-1α, sinomenine can inhibit epithelial-mesenchymal transition process of breast cancer SP cells. SIAH2 was identified as a target of miR-340-5p and was downregulated by it, and sinomenine can upregulate miR-340-5p. Hypoxia-induced downregulation of miR-340-5p and activation of SIAH2/HIF-1α pathway can be both counteracted by the sinomenine. Moreover, miR-340-5p inhibition and SIAH2 overexpression can partly counteract the anticancer effects of sinomenine. Taken together, sinomenine inhibits hypoxia-caused VM formation and metastasis of breast cancer SP cells by regulating the miR-340-5p/SIAH2 axis.