Phenotypic identification of subclones in multiple myeloma with different chemoresistant, cytogenetic and clonogenic potential.
Knowledge about clonal diversity and selection is critical to understand multiple myeloma (MM) pathogenesis, chemoresistance and progression. If targeted therapy becomes reality, identification and monitoring of intraclonal plasma cell (PC) heterogeneity would become increasingly demanded. Here we investigated the kinetics of intraclonal heterogeneity among 116 MM patients using 23-marker multidimensional flow cytometry (MFC) and principal component analysis, at diagnosis and during minimal residual disease (MRD) monitoring. Distinct phenotypic subclones were observed in 35/116 (30%) newly diagnosed MM patients. In 10/35 patients, persistent MRD was detected after 9 induction cycles, and longitudinal comparison of patient-paired diagnostic vs MRD samples unraveled phenotypic clonal tiding after therapy in half (5/10) of the patients. After demonstrating selection of distinct phenotypic subsets by therapeutic pressure, we investigated whether distinct fluorescence-activated cell-sorted PC subclones had different clonogenic and cytogenetic profiles. In half (5/10) of the patients analyzed, distinct phenotypic subclones showed different clonogenic potential when co-cultured with stromal cells, and in 6/11 cases distinct phenotypic subclones displayed unique cytogenetic profiles by interphase fluorescence in situ hybridization, including selective del(17p13). Collectively, we unravel potential therapeutic selection of preexisting diagnostic phenotypic subclones during MRD monitoring; because phenotypically distinct PCs may show different clonogenic and cytogenetic profiles, identification and follow-up of unique phenotypic-genetic myeloma PC subclones may become relevant for tailored therapy.
1] Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer/Consejo Superior de Investigaciones Científicas-Universidad de Salamanca (IBMCC, USAL-CSIC), Salamanca, Spain [2] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
T
T
Paíno
Clínica Universidad de Navarra, Centro de Investigaciones Médicas Aplicadas (CIMA), Pamplona, Spain.
B
B
Paiva
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Servicio General de Citometría y Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain.
J M
JM
Sayagués
Servicio General de Citometría y Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain.
I
I
Mota
Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, Coimbra, Portugal.
T
T
Carvalheiro
1] Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer/Consejo Superior de Investigaciones Científicas-Universidad de Salamanca (IBMCC, USAL-CSIC), Salamanca, Spain [2] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
L A
LA
Corchete
Hospital Universitario de Salamanca, Salamanca, Spain.
I
I
Aires-Mejía
Hospital Universitario de Salamanca, Salamanca, Spain.
J J
JJ
Pérez
Servicio General de Citometría y Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain.
M L
ML
Sanchez
Servicio General de Citometría y Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain.
P
P
Barcena
1] Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer/Consejo Superior de Investigaciones Científicas-Universidad de Salamanca (IBMCC, USAL-CSIC), Salamanca, Spain [2] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [3] Hospital Universitario de Salamanca, Salamanca, Spain.
E M
EM
Ocio
1] Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer/Consejo Superior de Investigaciones Científicas-Universidad de Salamanca (IBMCC, USAL-CSIC), Salamanca, Spain [2] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain.
L
L
San-Segundo
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Hospital Universitario de Salamanca, Salamanca, Spain.
M E
ME
Sarasquete
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Hospital Universitario de Salamanca, Salamanca, Spain.
R
R
García-Sanz
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Hospital Universitario de Salamanca, Salamanca, Spain.
M-B
MB
Vidriales
Hospital Germans Trias i Pujol, Badalona, Spain.
A
A
Oriol
Hospital Universitario de Canarias, Santa Cruz de Tenerife, Spain.
M-T
MT
Hernández
Hospital de Donostia, San Sebastian, Spain.
M-A
MA
Echeveste
Centro do Sangue e da Transplantação de Coimbra, Instituto Português do Sangue e da Transplantação, Coimbra, Portugal.
A
A
Paiva
Hospital Clínic, IDIBAPS, Salamanca, Spain.
J
J
Blade
Hospital 12 de Octubre, Madrid, Spain.
J-J
JJ
Lahuerta
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Servicio General de Citometría y Departamento de Medicina, Universidad de Salamanca, Salamanca, Spain.
A
A
Orfao
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Hospital Universitario de Salamanca, Salamanca, Spain.
M-V
MV
Mateos
1] Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain [2] Hospital Universitario de Salamanca, Salamanca, Spain.
N C
NC
Gutiérrez
Clínica Universidad de Navarra, Centro de Investigaciones Médicas Aplicadas (CIMA), Pamplona, Spain.
J F
JF
San-Miguel
D002469:Cell Separation; D018920:Coculture Techniques; D018450:Disease Progression; D019008:Drug Resistance, Neoplasm; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D017404:In Situ Hybridization, Fluorescence; D009101:Multiple Myeloma / Q000145:classification / Q000235:genetics*; D010641:Phenotype; D010950:Plasma Cells / Q000166:cytology; D025341:Principal Component Analysis; D011379:Prognosis; D017154:Stromal Cells / Q000166:cytology