Metallothioneins (MTs) are small cysteine-rich proteins that play important roles in metal homeostasis and protection against heavy metal toxicity, DNA damage, and oxidative stress. In humans, MTs have four main isoforms (MT1, MT2, MT3, and MT4) that are encoded by genes located on chromosome 16q13. MT1 comprises eight known functional (sub)isoforms (MT1A, MT1B, MT1E, MT1F, MT1G, MT1H, MT1M, and MT1X). Emerging evidence shows that MTs play a pivotal role in tumor formation, progression, and drug resistance. However, the expression of MTs is not universal in all human tumors and may depend on the type and differentiation status of tumors, as well as other environmental stimuli or gene mutations. More importantly, the differential expression of particular MT isoforms can be utilized for tumor diagnosis and therapy. This review summarizes the recent knowledge on the functions and mechanisms of MTs in carcinogenesis and describes the differential expression and regulation of MT isoforms in various malignant tumors. The roles of MTs in tumor growth, differentiation, angiogenesis, metastasis, microenvironment remodeling, immune escape, and drug resistance are also discussed. Finally, this review highlights the potential of MTs as biomarkers for cancer diagnosis and prognosis and introduces some current applications of targeting MT isoforms in cancer therapy. The knowledge on the MTs may provide new insights for treating cancer and bring hope for the elimination of cancer.

IMPORTANCEEvidence is needed regarding the introduction of high-risk human papillomavirus (hrHPV) testing into China's national cervical cancer screening program.OBJECTIVE To evaluate hrHPV testing as a new screening modality for the national program. DESIGN, SETTING, AND PARTICIPANTSThis population-based, multicenter, open-label, randomized clinical trial took place across 20 primary health care centers in urban and rural areas across China. At least 3000 women aged 35 to 64 years per site were invited to participate, for a total of 60 732 women evaluated.INTERVENTIONS At baseline, women were randomly assigned to cytology, hrHPV testing, or visual inspection with acetic acid and Lugol iodine (VIA/VILI) (rural only). Women who tested positive for hrHPV were randomized into cytology-triage, VIA/VILI-triage (rural only), or direct colposcopy arms. Regarding primary or triaging tests, women with cytological abnormalities or who tested positive with VIA/VILI were referred to colposcopy. After 24 months, combined screening of cytology, hrHPV testing, and VIA/VILI was performed, and all women with positive results were referred to colposcopy. MAIN OUTCOMES AND MEASURESThe primary outcomes were cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and CIN3+ yields. The secondary outcome was colposcopy referral rate.RESULTS A total of 60 732 women were included in this study, with median (interquartile range) age of 47 (41-52) years. Among urban women, 8955 were randomized to cytology and 18 176 to hrHPV genotyping; among rural women, 11 136 were randomized to VIA/VILI, 7080 to cytology, and 15 385 to hrHPV testing. Participants who tested positive for hrHPV with direct colposcopy had higher risk ratios for disease yields at baseline (urban hrHPV vs cytology, CIN2+ 2.2 [95% CI, 1.6-3.2] and CIN3+ 2.0 [95% CI, 1.2-3.3]; rural hrHPV vs cytology, 2.6 [95% CI, 1.9-4.0] and 2.7 [95% CI, 2.0-3.6]; rural hrHPV vs VIA/VILI, 2.0 [95% CI, 1.6-2.3] and 2.3 [95% CI, 1.8-3.1]). At 24 months, baseline-negative women in the hrHPV arm had significantly lower risk ratios than those with cytology, or VIA/VILI for CIN2+ (0.3 [95% CI, 0.2-0.5], 0.3 [95% CI, 0.2-0.6]) and CIN3+ (0.3 [95% CI, 0.1-0.6], 0.4 [95% CI, 0.2-0.8]) in rural sites. The colposcopy referral rate for hrHPV-positive rural women was reduced to 2.8% by cytology triage, with significantly higher CIN2+ yields than cytology (2.1 [95% CI, 1.3-2.6]) or VIA/VILI arm (1.6 [95% CI, 1.03-2.1]). Genotyping for hrHPV with cytology triage significantly reduced the colposcopy referral rate compared with cytology (0.8 [95% CI, 0.7-0.9]) for urban women. CONCLUSIONS AND RELEVANCEIn this randomized clinical trial, testing for hrHPV was an effective primary screening method in primary health care centers. Incorporating hrHPV testing (polymerase chain reaction-based for urban areas, hybrid capture-based for rural areas) into China's national screening program is reasonable.

Based on currently available evidence, the findings of this meta-analysis suggest that LAD bears little prognostic or therapeutic benefit in patients with uterine sarcoma. Systematic LAD may not be recommended in patients with uLMS or ESS unless the patient has obvious extrauterine involvement, clinically suspicious enlarged nodes, or advanced sarcomas.