Neutrophil biology and the next generation of myeloid growth factors

Effect of acupuncture in myelosuppression and quality of life in women with breast cancer undergoing chemotherapy: a randomized clinical study

OBJECTIVE

This study aimed to evaluate the effect of acupuncture on myelosuppression and quality of life in women with breast cancer during treatment with anthracyclines (ANT).

METHODS

Women with indication for ANT chemotherapy were randomized into two groups: acupuncture group (AG) and control group (CG). A quality of life questionnaire (FACT-G) and peripheral blood levels of the participants were evaluated before and at the end of treatment. The AG was submitted to an acupuncture intervention, starting before the first chemotherapy infusion, and continuing throughout the treatment.

RESULTS

A total of 26 women were randomized into 2 groups: AG (10) and CG (16). Of these, 26.9% had a dense dose indication according to the service's protocol for the administration of granulocyte-stimulating factor (G-CSF) from the first cycle, not participating in the analysis. The need for secondary prophylaxis with G-CSF occurred in 72.7% in the control group versus 12% in the acupuncture group. Regarding quality of life (QoL), it was observed that the groups did not initially differ from each other. At the end of the treatment, there was a significant difference in the AG for the physical (GP) (p-value=0.011), social/family (GS) (p-value=0.018), and functional (GF) (p-value=0.010) domains, regarding the initial and final FACT-G showed a difference between the groups, where the GA average at the end rose from 80.68 to 90.12 (p-value = 0.004) and in the CG the average dropped from 81.95 to 70.59 (p-value=0.003).

CONCLUSION

Acupuncture was efficient in the secondary prophylaxis of myelosuppression during chemotherapy and the quality of life of women during treatment has increased.

TRIAL REGISTRATION

Brazilian Registry of Clinical Trials - Rebec on 06/28/2018, registration number U1111-1216-3921, Rebec Trial RBR-7BWJ6R.

Mechanism of drug extrusion by brain endothelial cells via lysosomal drug trapping and disposal by neutrophils

Located at the apical (blood-facing) site of brain capillary endothelial cells that form the blood–brain barrier (BBB), the efflux transporter P-glycoprotein (Pgp) restricts the brain entry of various lipophilic xenobiotics, which contributes to BBB function. Pgp may become saturated if exposed to too-high drug concentrations. Here, we demonstrate a second-line defense mechanism in human brain capillary endothelial cells—that is, Pgp-mediated intracellular lysosomal drug trapping. Furthermore, we describe a mechanism of drug disposal at the BBB, which is shedding of lysosomal Pgp/substrate complexes at the apical membrane of human and porcine BBB endothelial cells and subsequent phagocytosis by neutrophils. Thus, we have discovered a fascinating mechanism of how Pgp might contribute to brain protection.

The blood–brain barrier protects the brain against a variety of potentially toxic compounds. Barrier function results from tight junctions between brain capillary endothelial cells and high expression of active efflux transporters, including P-glycoprotein (Pgp), at the apical membrane of these cells. In addition to actively transporting drugs out of the cell, Pgp mediates lysosomal sequestration of chemotherapeutic drugs in cancer cells, thus contributing to drug resistance. Here, we describe that lysosomal sequestration of Pgp substrates, including doxorubicin, also occurs in human and porcine brain endothelial cells that form the blood–brain barrier. This is followed by shedding of drug-sequestering vesicular structures, which stay attached to the apical side of the plasma membrane and form aggregates (“barrier bodies”) that ultimately undergo phagocytosis by neutrophils, thus constituting an as-yet-undescribed mechanism of drug disposal. These findings introduce a mechanism that might contribute to brain protection against potentially toxic xenobiotics, including therapeutically important chemotherapeutic drugs.

Polyphenon [corrected] E enhances the antitumor immune response in neuroblastoma by inactivating myeloid suppressor cells

PURPOSE

Neuroblastoma is a rare childhood cancer whose high risk, metastatic form has a dismal outcome in spite of aggressive therapeutic interventions. The toxicity of drug treatments is a major problem in this pediatric setting. In this study, we investigated whether Polyphenon E, a clinical grade mixture of green tea catechins under evaluation in multiple clinical cancer trials run by the National Cancer Institute (Bethesda, MD), has anticancer activity in mouse models of neuroblastoma.

EXPERIMENTAL DESIGN

We used three neuroblastoma models: (i) transgenic TH-MYCN mouse developing spontaneous neuroblastomas; (ii) nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice xenotransplanted with human SHSY5Y cells; and (iii) A/J mice transplanted with syngeneic Neuro 2A cells. Mice were randomized in control and Polyphenon E-drinking groups. Blood from patients with neuroblastoma and normal controls was used to assess the phenotype and function of myeloid cells.

RESULTS

Polyphenon E reduced the number of tumor-infiltrating myeloid cells, and inhibited the development of spontaneous neuroblastomas in TH-MYCN transgenic mice. In therapeutic models of neuroblastoma in A/J, but not in immunodeficient NOD/SCID mice, Polyphenon E inhibited tumor growth by acting on myeloid-derived suppressor cells (MDSC) and CD8 T cells. In vitro, Polyphenon E impaired the development and motility of MDSCs and promoted differentiation to more neutrophilic forms through the 67 kDa laminin receptor signaling and induction of granulocyte colony-stimulating factor. The proliferation of T cells infiltrating a patient metastasis was reactivated by Polyphenon E.

CONCLUSIONS

These findings suggest that the neuroblastoma-promoting activity of MDSCs can be manipulated pharmacologically in vivo and that green tea catechins operate, at least in part, through this mechanism.

Immunostimulation of sugar cane extract on neutrophils to Salmonella typhimurium infection in mice

The aim of this study was to evaluate the immunomodulatory effects of sugar cane extract (SCE) on the biological activities of neutrophils in mice. Six-week-old BALB/c mice were fed 1250 mg/kg of SCE once. The generation, migration and biological functions of neutrophils and the survival rates of the mice in response to Salmonella typhimurium infection were evaluated. The results show that the numbers of both bone marrow cells and neutrophils were significantly increased in response to SCE administration (p < 0.05) compared with controls. The migration, phagocytosis and H₂O₂ generation of neutrophils were all significantly enhanced in SCE-treated mice (p < 0.05). After challenge with S. typhimurium (lethal dose, 50% (LD₅₀), SCE-treated mice had a 19.2% higher survival rate and milder hepatic lesions than the controls. Additionally, fewer invasive bacteria were recovered from the spleens of SCE-treated mice. In conclusion, our results suggest that SCE has a positive regulatory effect on the biological function of mouse neutrophils that may increase host resistance against bacterial infections.

Advances in the treatment of neutropenia

PURPOSE OF REVIEW

The present review updates treatment of neutropenia from articles published from January 2008 through April 2009.

RECENT FINDINGS

Chemotherapy-induced neutropenia occurs most commonly in the first cycle of treatment. Older patients, patients with multiple comorbidities, and those receiving more myelotoxic drugs are prone to develop neutropenia and its complications. Current guidelines recommend the prophylactic use of the myeloid growth factors for the first cycle of chemotherapy for patients with more than a 20% risk of febrile neutropenia. Meta analysis from randomized trials shows that granulocyte colony-stimulating factor prophylaxis is associated with patients receiving more intensive chemotherapy, having better survival, but also having a higher risk of secondary acute myeloid leukemia. Antibiotics are standard treatment of febrile neutropenia and are increasingly used for prophylaxis in 'low-risk' patients.

SUMMARY

The myeloid growth factor granulocyte colony-stimulating factor has radically changed our approach to the prevention of febrile neutropenia. Antibiotics remain the mainstay of treatment of febrile neutropenia.