Squamous cell carcinomas (SCCs) originate in stratified epithelia, with a small subset becoming metastatic. Epithelial stem cells are targets for driver mutations that give rise to SCCs, but it is unknown whether they contribute to oncogenic multipotency and metastasis. We developed a mouse model of SCC by targeting two frequent genetic mutations in human SCCs, oncogene Kras G12D activation and Smad4 deletion, to mouse keratin 15-expressing (K15 + ) stem cells. We show that transgenic mice developed multilineage tumors, including metastatic SCCs. Among cancer stem cell-enriched (CSC-enriched) populations, those with increased side population (SP) cells correlated with epithelial-mesenchymal transition (EMT) and lung metastasis. We show that microRNA-9 (miR-9) contributed to SP expansion and metastasis, and miR-9 inhibition reduced the number of SP cells and metastasis. Increased miR-9 was detected in metastatic human primary SCCs and SCC metastases, and miR-9-transduced human SCC cells exhibited increased invasion. We identified α-catenin as a predominant miR-9 target. Increased miR-9 in human SCC metastases correlated with α-catenin loss but not E-cadherin loss. Our results demonstrate that stem cells with Kras G12D activation and Smad4 depletion can produce tumors that are multipotent and susceptible to EMT and metastasis. Additionally, tumor initiation and metastatic properties of CSCs can be uncoupled, with miR-9 regulating the expansion of metastatic CSCs. IntroductionSquamous cell carcinomas (SCCs) are derived from stratified epithelia present within the skin and oral cavity. A subset of aggressive SCCs become metastatic and lead to metastasis-associated death. The rate of metastasis in skin SCCs ranges from 0.1% to 10% (1), with poorly differentiated tumors and those with greater vertical tumor thickness having an increased risk of metastasis (2). Genetic alterations and intrinsic tumor cell properties controlling SCC metastasis are largely unknown. Genetically engineered mice provide a powerful tool for dissecting driver mutations that contribute to SCC initiation and metastasis. To date, very few genetic mutations causing spontaneous SCC formation and metastasis have been found, particularly metastasis to the lung, which is the leading cause of SCC-associated death (3). Mice with a Smad4 deletion in stratified epithelia develop spontaneous SCCs in the skin, oral cavity, and forestomach (4-6). Among these models, oral SCCs metastasize to lymph nodes (4), whereas skin and forestomach SCCs do not metastasize (5, 6).Because stratified epithelia undergo constant self-renewal and rapid turnover, it is believed that driver mutations for SCCs must initially occur in resident stem cells that renew these epithelia throughout life. In mouse skin, the hair follicle bulge harbors

Background and aims We aim to assess the safety and immunogenicity of inactivated whole-virion SARS-CoV-2 vaccines in patients with chronic liver diseases (CLD) in this study. Methods This was a prospective, multi-center, open-label study. Participants aged over 18 years with confirmed CLD and healthy volunteers were enrolled. All participants received 2 doses of inactivated whole-virion SARS-CoV-2 vaccines. Adverse reactions were recorded within 14 days after any dose of SARS-CoV-2 vaccine, laboratory testing results were collected after the second dose, and serum samples of enrolled subjects were collected and tested for SARS-CoV-2 neutralizing antibodies at least 14 days after the second dose. Results A total of 581 participants (437 patients with CLD and 144 healthy volunteers) were enrolled from 15 sites in China. Most adverse reactions were mild and transient, and injection site pain (36 [8.2%]) was the most frequently reported adverse event. Three participants had Grade 3 aminopherase elevation (defined as alanine aminopherase>5 upper limits of normal) after the second dose of inactivated whole-virion SARS-CoV-2 vaccination, and only one of them was judged as severe adverse event potentially related to SARS-CoV-2 vaccination. The positive rates of SARS-CoV-2 neutralizing antibodies were 76.8% in non-cirrhotic CLD group, 78.9% in compensated cirrhotic group, 76.7% in decompensated cirrhotic group (P=0.894 among CLD subgroups) and 90.3% in healthy controls (P=0.008 versus CLD group). Conclusion Inactivated whole-virion SARS-CoV-2 vaccines are safe in patients with CLD. Patients with CLD had lower immunological response to SARS-CoV-2 vaccines than healthy population. The immunogenicity is similarly low in non-cirrhotic CLD, compensated cirrhosis and decompensated cirrhosis.

Background: Pyrotinib is an irreversible pan-ErbB inhibitor targeting epidermal growth factor receptor, human epidermal growth factor receptor 2 (HER2), and HER4. This randomized, double-blinded phase 3 study evaluated the efficacy and safety of pyrotinib plus capecitabine for HER2-positive local relapsed or metastatic breast cancer.Methods: Patients who had been treated with trastuzumab and taxanes were randomized (2:1) to receive either oral pyrotinib or placebo (400 mg, qd) plus capecitabine (1,000 mg/m 2 , bid on days 1-14) for 21-day cycles, using stratified block randomization. The primary endpoint was progression-free survival (PFS) per independent review committee. Patients who progressed on placebo plus capecitabine received subsequent pyrotinib monotherapy. This study is registered with ClinicalTrials.gov (NCT02973737), enrollment is closed.

We report that K5.Smad7 mice, which express Smad7 transgene by a keratin-5 promoter, were resistant to radiation-induced oral mucositis, a painful oral ulceration. In addition to NF-κB activation known to contribute to oral mucositis, we found activated TGF-β signaling in oral mucositis. Smad7 dampened both pathways to attenuate inflammation, growth inhibition and apoptosis. Additionally, Smad7 promoted oral epithelial migration to close the wound. Further analyses revealed that TGF-β signaling Smads and their co-repressor CtBP1 transcriptionally repressed Rac1, and Smad7 abrogated this repression. Knocking down Rac1 in mouse keratinocytes abrogated Smad7-induced migration. Topically applying Smad7 protein with a cell permeable Tat-tag (Tat-Smad7) to oral mucosa showed preventive and therapeutic effects on radiation-induced oral mucositis in mice. Thus, we have identified novel molecular mechanisms involved in oral mucositis pathogenesis and our data suggest an alternative therapeutic strategy to block multiple pathological processes of oral mucositis.