Code:

var utxo = new bitcore.Transaction.UnspentOutput({
  "txid" : "e0c6b736e86e8dccd63bbc27f35142b413bd991a410ef50f14cd56fa1a783a1e",
  "vout" : 0,
  "address" : "2NCAeo5p1Pg8VVupFFumCd3PYz551VAZWLJ",
  "scriptPubKey" : "OP_HASH160 20 0xcf8d0490cba6d7ca817323cf0c337fbd0a3de539 OP_EQUAL",
  "amount" : 10000000
});

var multiSigTx = new bitcore.Transaction()
    .from(utxo, pubKeys, 2)
    .to("mwFLeaw5LMAPvoz1hP6qQhHbHkHq8WxM2t", 90000)
    .fee(9000)
    .change("mwFLeaw5LMAPvoz1hP6qQhHbHkHq8WxM2t")
    .sign(privKeys);


var txSerialized = multiSigTx.serialize(true);
insight.broadcast(txSerialized, function(err, returnedTxId) {
  if (err) {
    console.log(err);
  } else {
    console.log("Sent coins, tx id is: ");
    console.log(returnedTxId);
  }
});

Result:

Transaction rejected by network (code -26). Reason: 16: bad-txns-in-belowout