Zoledronic acid ameliorates the effects of endocrine therapy on bone health in women with early-stage breast cancer

SCUBE2 mediates bone metastasis of luminal breast cancer by modulating immune-suppressive osteoblastic niches

Estrogen receptor (ER)-positive luminal breast cancer is a subtype with generally lower risk of metastasis to most distant organs. However, bone recurrence occurs preferentially in luminal breast cancer. The mechanisms of this subtype-specific organotropism remain elusive. Here we show that an ER-regulated secretory protein SCUBE2 contributes to bone tropism of luminal breast cancer. Single-cell RNA sequencing analysis reveals osteoblastic enrichment by SCUBE2 in early bone-metastatic niches. SCUBE2 facilitates release of tumor membrane-anchored SHH to activate Hedgehog signaling in mesenchymal stem cells, thus promoting osteoblast differentiation. Osteoblasts deposit collagens to suppress NK cells via the inhibitory LAIR1 signaling and promote tumor colonization. SCUBE2 expression and secretion are associated with osteoblast differentiation and bone metastasis in human tumors. Targeting Hedgehog signaling with Sonidegib and targeting SCUBE2 with a neutralizing antibody both effectively suppress bone metastasis in multiple metastasis models. Overall, our findings provide a mechanistic explanation for bone preference in luminal breast cancer metastasis and new approaches for metastasis treatment.

IL-21 Increases the Reactivity of Allogeneic Human Vγ9Vδ2 T Cells Against Primary Glioblastoma Tumors

Glioblastoma multiforme (GBM) remains the most frequent and deadliest primary brain tumor in adults despite aggressive treatments, because of the persistence of infiltrative and resistant tumor cells. Nonalloreactive human Vγ9Vδ2 T lymphocytes, the major peripheral γδ T-cell subset in adults, represent attractive effectors for designing immunotherapeutic strategies to track and eliminate brain tumor cells, with limited side effects. We analyzed the effects of ex vivo sensitizations of Vγ9Vδ2 T cells by IL-21, a modulating cytokine, on their cytolytic reactivity. We first showed that primary human GBM-1 cells were naturally eliminated by allogeneic Vγ9Vδ2 T lymphocytes, through a perforin/granzyme-mediated cytotoxicity. IL-21 increased both intracellular granzyme B levels and cytotoxicity of allogeneic human Vγ9Vδ2 T lymphocytes in vitro. Importantly, IL-21-enhanced cytotoxicity was rapid, which supports the development of sensitization(s) of γδ T lymphocytes before adoptive transfer, a process that avoids any deleterious effect associated with direct administrations of IL-21. Finally, we showed, for the first time, that IL-21-sensitized allogeneic Vγ9Vδ2 T cells significantly eliminated GBM tumor cells that developed in the brain after orthotopic administrations in vivo. Altogether our observations pave the way for novel efficient stereotaxic immunotherapies in GBM patients by using IL-21-sensitized allogeneic human Vγ9Vδ2 T cells.

Bisphosphonate use after estrogen receptor-positive breast cancer and risk of contralateral breast cancer

BACKGROUND

A growing body of evidence suggests that nitrogenous bisphosphonates may reduce the risk of developing a first breast cancer and may prevent metastases among breast cancer survivors. However, their impact on risk of second primary contralateral breast cancer is uncertain.

METHODS

Within a nested case-control study among women diagnosed with a first primary estrogen receptor-positive invasive breast cancer at ages 40-79 years, we assessed the association between post-diagnostic bisphosphonate use and risk of second primary contralateral breast cancer. We used multivariable-adjusted conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) comparing 351 contralateral breast cancer case subjects with 662 control subjects (ie, breast cancer patients not diagnosed with contralateral breast cancer) who were incidence density-matched on county; race/ethnicity; and age at, year of, and stage at first breast cancer diagnosis. We performed sensitivity analyses with respect to bisphosphonate type and confounding by indication. All statistical tests were two-sided.

RESULTS

Current use of any nitrogenous bisphosphonate and use specifically of alendronate were both associated with reduced risks of contralateral breast cancer compared with never use (OR = 0.41, 95% CI = 0.20 to 0.84 and OR = 0.39, 95% CI = 0.18 to 0.88, respectively). The risk of contralateral breast cancer further declined with longer durations of bisphosphonate use among current users (P(trend) = .03). Results were similar in analyses restricted to patients with a history of osteoporosis or osteopenia.

CONCLUSIONS

Bisphosphonate use was associated with a substantial reduction in risk of contralateral breast cancer. If this finding is confirmed in additional studies, nitrogenous bisphosphonate therapy may be a feasible approach for contralateral breast cancer risk reduction.