Altered genetic features in cancer cells lead to a high rate of aerobic glycolysis and metabolic reprogramming that is essential for increased cancer cell viability and rapid proliferation. Pyruvate kinase muscle (PKM) is a rate-limiting enzyme in the final step of glycolysis. Herein, we report that PKM is a potential therapeutic target in triple-negative breast cancer (TNBC) cells. We found that PKM1 or PKM2 is highly expressed in TNBC tissues or cells. Knockdown of PKM significantly suppressed cell proliferation and migration, and strongly reduced S phase and induced G2 phase cell cycle arrest by reducing phosphorylation of the CDC2 protein in TNBC cells. Additionally, knockdown of PKM significantly suppressed NF-kappa B (nuclear factor kappa-light-chain-enhancer of activated B cells) activity by reducing the phosphorylation of p65 at serine 536, and also decreased the expression of NF-kappa B target genes. Taken together, PKM is a potential target that may have therapeutic implications for TNBC cells.

Panphila evaluated pyrotinib plus trastuzumab, docetaxel and carboplatin as neoadjuvant therapy for early breast cancer (BC), and investigated the predictive role of immune cell subpopulations. In this multicentre phase 2 study, patients with human epidermal growth factor receptor 2-positive, stage T2-3N0-3M0 BC received pyrotinib 400 mg once daily plus docetaxel (75 mg/m², day 1), carboplatin (6 mg/mL/min, day 1) and trastuzumab (8 mg/kg loading dose and 6 mg/kg maintenance dose, day 1) for 6 cycles of 21 days each. Simon's 2-stage design was adopted. The primary end-point was pathological complete response (pCR, ypT0/is ypN0) rate. Tumour-infiltrating lymphocytes (TILs) were assessed by haematoxylin and eosin staining and multiplex immunohistochemistry. In the modified intention-to-treat population (n = 69), 38 patients (55.1%) achieved pCR. In the safety population (n = 74), the most common grade ≥3 adverse events were diarrhoea (43.2%), anaemia (37.8%), vomiting (16.2%) and platelet count decrease (10.8%). No treatment-related deaths occurred. Analysis of single immune subpopulations revealed a significant association of pCR with higher baseline infiltration by stromal (s)-CD20+, s-CD8+ and s-CD4+ TILs. Unsupervised hierarchical clustering of stromal immune markers identified a group of patients characterised by high s-CD20+, s-CD8+, s-CD4+ and s-FOXP3+ immune cells infiltration, which was independently associated with pCR. Neoadjuvant pyrotinib plus trastuzumab-based chemotherapy exhibits promising efficacy and manageable toxicity in patients with human epidermal growth factor receptor 2-positive early BC, and thus phase 3 trials are warranted. Our findings also contribute to understanding the potential role of the immune microenvironment in response to neoadjuvant pyrotinib-based therapy.

Metastasis is the leading cause of cancer-related death. The interactions between circulating tumor cells and endothelial adhesion molecules in distant organs is a key step during extravasation in hematogenous metastasis. Surgery is a common intervention for most primary solid tumors. However, surgical trauma-related systemic inflammation facilitates distant tumor metastasis by increasing the spread and adhesion of tumor cells to vascular endothelial cells (ECs). Currently, there are no effective interventions to prevent distant metastasis. Here, we show that HECTD3 deficiency in ECs significantly reduces tumor metastasis in multiple mouse models. HECTD3 depletion downregulates expression of adhesion molecules, such as VCAM-1, ICAM-1 and E-selectin, in mouse primary ECs and HUVECs stimulated by inflammatory factors and inhibits adhesion of tumor cells to ECs both in vitro and in vivo. We demonstrate that HECTD3 promotes stabilization, nuclear localization and kinase activity of IKKα by ubiquitinating IKKα with K27- and K63-linked polyubiquitin chains at K296, increasing phosphorylation of histone H3 to promote NF-κB target gene transcription. Knockout of HECTD3 in endothelium significantly inhibits tumor cells lung colonization, while conditional knockin promotes that. IKKα kinase inhibitors prevented LPS-induced pulmonary metastasis. These findings reveal the promotional role of the HECTD3-IKKα axis in tumor hematogenous metastasis and provide a potential strategy for tumor metastasis prevention.

Immunotherapy combined with chemotherapy has been demonstrated to be effective in early triple-negative breast cancer (TNBC). In this single-arm, phase II study with Simon’s two-stage design, we investigated the efficacy and safety of neoadjuvant camrelizumab plus chemotherapy in patients with early TNBC (NCT04213898). Eligible female patients aged 18 years or older with histologically confirmed treatment-naïve early TNBC were treated with camrelizumab (200 mg, on day 1), nab-paclitaxel (125 mg/m², on days 1, 8, and 15), and epirubicin (75 mg/m², on day 1) every three weeks for six cycles. The primary end point was the pathological complete response; secondary endpoints included safety, objective response rate, and long-term survival outcomes of event-free survival, disease-free survival, and distant disease-free survival. A total of 39 patients were enrolled between January 2020 and October 2021. Twenty-five patients achieved a pathological complete response (64.1%, 95%CI: 47.2, 78.8). The objective response rate was 89.7% (95%CI: 74.8, 96.7), including 35 patients with partial responses. Treatment-related adverse events of grade 3 or 4 occurred in 30 (76.9%) patients. In conclusion, the trial meets the prespecified endpoints showing promising efficacy and manageable safety of neoadjuvant camrelizumab plus nab-paclitaxel and epirubicin chemotherapy in female patients with early TNBC. Long-term survival outcomes are still pending.

STING (Stimulator of interferon genes) is known as an important adaptor protein or direct sensor in the detection of nucleotide originating from pathogens or the host. The implication of STING during pulmonary microbial infection remains unknown to date. Herein, we showed that STING protected against pulmonary S.aureus infection by suppressing necroptosis. STING deficiency resulted in increased mortality, more bacteria burden in BALF and lungs, severe destruction of lung architecture, and elevated inflammatory cells infiltration and inflammatory cytokines secretion. STING deficiency also had a defect in bacterial clearance, but did not exacerbate pulmonary inflammation during the early stage of infection. Interestingly, TUNEL staining and LDH release assays showed that STING^-/- mice had increased cell death than WT mice. We further demonstrated that STING^-/- mice had decreased number of macrophages accompanied by increased dead macrophages. Our in vivo and in vitro findings further demonstrated this cell death as necroptosis. The critical role of necroptosis was detected by the fact that MLKL^-/- mice exhibited decreased macrophage death and enhanced host defense to S.aureus infection. Importantly, blocking necroptosis activation rescued host defense defect against S.aureus pneumonia in STING^-/- mice. Hence, these results reveal an important role of STING in suppressing necroptosis activation to facilitate early pathogen control during pulmonary S.aureus infection.