Background Interleukin-6 (IL-6) has been demonstrated to be a critical factor for breast cancer malignancy. However, the molecular mechanisms by which IL-6 induce breast cancer cells epithelial–mesenchymal-transition (EMT) and stemness remain elusive. Methods Breast cancer cell lines T47D and MCF7 were exposed to IL-6, the expression of PIM1 was examined by quantitative real-time PCR (qRT-PCR) and western blot. Luciferase reporter assay was used to determine the transcriptional modulation of PIM1 by IL-6 and STAT3 inhibitor. Transwell assay was used to detect the invading ability of breast cancer cells induced by IL-6 or PIM1. The expressions of EMT and stemness markers were determined by qRT-PCR. Results IL-6 promoted PIM1 expression in a dose- and time-dependent manner, and this induction could be abrogated by inhibiting STAT3 activation, subsequently suppressing the transcriptional level of PIM1. Moreover, we noticed that knocking down of PIM1 in cells which was exposed to IL-6 significantly impaired the invasion ability and the expression of EMT and stemness markers. On the contrary, overexpression of PIM1 promoted cell invasion and upregulated the expression of EMT and stemness markers. In addition, we demonstrated that c-myc, the cofactor of PIM1, involved in the pro-oncogenic roles of PIM1. Knocking down of c-myc attenuated the PIM1-induced cell EMT and stemness. Conclusion This study proposed the upregulation of PIM1 by IL-6 contributed to breast cancer cell aggressiveness and targeting PIM1 or c-myc could be novel approaches for breast cancer treatment.

Chemoresistance is a major obstacle to effective breast cancer chemotherapy. However, the underlying molecular mechanisms remain unclear. The long noncoding RNA H19 (H19) is involved in various stages of tumorigenesis, however, its role in doxorubicin resistance remains unknown. The goal of this study was to evaluate the role of H19 in the development of doxorubicin-resistant breast cancer. Quantitative real-time PCR (qRT-PCR) analyzed H19 expression in chemotherapy-resistant and sensitive breast cancer tissues. Both knockdown and overexpression of H19 were used to assess the sensitivity to doxorubicin in breast cancer cells in vitro and in vivo . qRT-PCR and Western blot were used to explore the doxorubicin resistance mechanism of H19. We observed that the H19 expression was significantly upregulated in chemotherapy-resistant breast cancer tissues and doxorubicin-resistant breast cancer cell lines. Knockdown of H19 enhanced the sensitivity to doxorubicin both in vitro and in vivo . While H19 overexpression developed doxorubicin-resistant in breast cancer cells both in vitro and in vivo . Furthermore, it was revealed that H19 negatively regulated PARP1 expression in breast cancer cells following doxorubicin treatment. Knockdown of H19 sensitized breast cancer cells to doxorubicin by promoting PARP1 upregulation. H19 overexpression could recapitulate doxorubicin resistance by PARP1 downregulation. Our findings revealed that H19 plays a leading role in breast cancer chemoresistance development, mediated mainly through a H19-PARP1 pathway.

T-cell-based immunotherapy and immune checkpoint blockade have been successfully used to treat several human solid cancers. The present study attempted to investigate the feasibility and efficacy of the antitumor effect of adoptive cell therapy along with programmed cell death protein 1 (PD-1) inhibitor on triplenegative breast cancer (TNBC). Tumor infiltration lymphocytes (TILs) from TNBC mouse tumor tissues were isolated and expanded, and TILs for adoptive cell therapy (TILs-ACT) were applied in combination with a PD-1 inhibitor to the TNBC mouse model. The pre-and post-therapy antitumor efficacy, cytokine secretion, and pathological changes were assessed both in vitro and in vivo. We found that TILs exhibited higher IFN-γ and TNF-α secretion than conventional T cells. The TILs-ACT combined with PD-1 inhibitor promoted active T-cell infiltration into the tumor tissue and exerted a strong antitumor effect in an in vivo model. Additionally, the strategy could downregulate the expression of inhibitory marker PD-1 on TILs. In conclusion, PD-1 blockade regulated T-cell exhaustion that synergized with adoptive TIL transfer immunotherapy, leading to eradication of established TNBC tumors. These findings might be useful in developing a feasible and effective therapeutic approach for TNBC.

BackgroundMitoxantrone hydrochloride injection for tracing (MHI), a new strategy to identify lymph nodes, has not been tested for axillary node staging in breast cancer. This multicenter, self-controlled, non-inferiority trial aimed to evaluate MHI’s efficacy and safety in sentinel lymph node biopsy (SLNB).MethodsThe trial was conducted across seven hospitals from December 2019 to December 2020. Patients with early-stage breast cancer received MHI and technetium-99m (99mTc) during the surgery. Sentinel node detection rates were compared between MHI and 99mTc to evaluate non-inferiority and concordance. Non-inferiority was valid if the lower limit of the 95% CI of sentinel node relative detection rate difference was ≥−5%.ResultsSLN relative detection rate of MHI was 97.31% (362/372). Of the SLNs, 79.69% (871/1093) were co-detected by both tracers. Of the patients, 4.13% (16/387) had adverse events and recovered during the follow-up.ConclusionsMHI is a lymphatic tracer with comparable efficacy to radionuclides and can be used alone or in combination with radioactive substances for SLNB.Clinical Trial Registrationhttp://www.chinadrugtrials.org.cn, CTR20192435.

Aim:Mitoxantrone is an antineoplastic antibiotic used in the treatment of acute leukemia, lymphoma, prostate and breast cancer. Mitoxantrone Hydrochloride Injection for tracing has a high degree of lymph node tropism by changing the dosage form, which penetrates into lymphatic capillaries through the interstitial space and enriches regional lymph nodes through the gland to stain the lymph nodes blue to achieve lymph node tracing effect. This study is aim to evaluate the efficacy and safety of Mitoxantrone Hydrochloride injection(MHI) for tracing sentinel lymph nodes in patients with early-stage breast cancer.Materials & methods: This study was a phase 3, multicenter, self-controlled, non-inferiority trial designed to assess the efficacy and safety of sentinel lymph node tracing with the investigational drug in patients with early-stage breast cancer. All subjects received MHI combined with Technetium-99m(99mTc-Sc), prior to SLNB. The sentinel node identification rate was compared between MHI and 99mTc-Sc to evaluate non-inferiority and concordance. Results: Data were collected from 381 patients in 6 centers all across China. The SLN detection rate was 96.9% (369/381) when using MHI and 97.4% (371/381) when using the standard technique(Table 1). There was no significant difference in the success rate of SLN detection between the two groups(P > 0.05). Since the lower limit of 95% confidence interval was greater than or equal to -5%, the success rate of SLN detection of MHI was non-inferior to that of 99mTc-Sc. In the combination group, 380 cases (99.5%) were successfully detected with SLN. 202 nodes (13.1%) were detected by the MHI but not by the 99mTc-Sc, and 222 nodes (14.4%) were detected by the 99mTc-Sc but not by the MHI(Table 2). All adverse events recovered within one month after intervention.Conclusion: This prospective, multicenter study has shown the Mitoxantrone Hydrochloride injection for tracing to be non-inferior to the standard technique (99mTc-Sc) for breast SLNB. The Mitoxantrone Hydrochloride injection for tracing can be used alone or combined with radioactive material.Key words:Mitoxantrone Hydrochloride injection(MHI), Tracing, Technetium-99m(99mTc-Sc), sentinel lymph node (SLN), Early-Stage Breast Cancer. Attachments: Table 1.SLN detection rate - comparing the Mitoxantrone Hydrochloride Injection and 99mTc-Sc for TracingSLN detection rates [n (%)]Mitoxantrone Hydrochloride Injection for TracingTotalAt least one node detectedNo nodes detected99mTc-ScPositive361 (94.8%)10 (2.6%)371 (97.4%)Negative8 (2.1%)2 (0.5%)10 (2.6%)Total369 (96.9%)12 (3.1%)381(100%) Table 2.Detected nodes-comparing the Mitoxantrone Hydrochloride Injection and 99mTc-Sc for TracingPer node detection rates [n (%)]Mitoxantrone Hydrochloride Injection for TracingTotalPositiveNegative99mTc-ScPositive869 (56.3%)222 (14.4%)1091 (70.7%)Negative202 (13.1%)251 (16.3%)453 (29.3%)Total1071 (69.4%)473 (30.6%)1544 (100%) Citation Format: Benlong Yang, Dechuang Jiao, Jiajian Chen, Chunjian Wang, Lidan Jin, Wenhe Zhao, Xueqiang Gao, Haibo Wang, Jun Li, Haidong Zhao, Di Wu, Zhiming Fan, Shujun Wang, Zhenzhen Liu, Yongsheng Wang, Jiong Wu. A phase 3, multicenter, self-controlled, non-inferiority trial comparing mitoxantrone hydrochloride injection for tracing versus technetium-99m in the detection of axillary sentinel nodes in patients with early-stage breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-01-10.